Beyond the 99% Invisible City

Summary

99% Invisible, "Beyond the 99% Invisible City"

Host: Roman Mars
Episode Date: December 30, 2025

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Overview

This special episode of 99% Invisible, hosted by Roman Mars with regular contributor Kurt Kohlstedt, invites listeners on a thoughtful journey "beyond" the stories of their hit book The 99% Invisible City. The episode shares four previously unreleased mini-stories, each reflecting the book's central themes: Infrastructure, Urbanism, Geography, and Architecture. Designed as both a celebration of overlooked design and a preview of a forthcoming expanded edition, the episode stitches together fan-fueled story leads, historical rabbit holes, and delightfully quirky details of the built environment.

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Key Discussion Points & Insights

1. Behind the Scenes: Narration, Books, and Chapters

(Timestamps 01:02–03:15)

• Roman Mars coaches Kurt on his iconic introduction, highlighting the show's signature tone—part gravitas, part warmth.

  • Notable moment [01:54]: "That's great. I love it. Print it." —Roman Mars

• The hosts reflect on the success and global impact of their book, The 99% Invisible City, and discuss their decision to share four new stories, each tied to a main chapter of the book:

  • Infrastructure, Urbanism, Geography, Architecture

• Each story reflects deep listener engagement and the show's love of uncovering design's hidden stories.

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2. Infrastructure: The Surprising History of Stop Signs

(Timestamps 03:17–13:52)

The Story

Prompted by a listener's question about blue stop signs in Hawaii, Kurt explores the evolution and reasoning behind stop sign design.

Insights

• Origins:

  • William Phelps Eno, dubbed "the father of traffic safety," played a pivotal (if often overlooked) role in the development of early traffic systems, advocating for innovations like roundabouts and signage [04:36–06:15].

• Shape Theory:

  • The octagonal stop sign became standard in 1923 via the Mississippi Valley Association of State Highway Departments [08:00].
  • Roman Mars reading NYT excerpt about shape coding: [09:29]

    "The recommendations were based on a simple, albeit not exactly intuitive idea. The more sides a sign has, the higher the danger level it invokes."

• Color Evolution:

  • Initially, stop signs were yellow (better at night, due to limitations in reflective materials) and became standard in red in the 1950s as technology improved [11:26].
  • Red ties in with other "stop" signals, like traffic lights.

• Blue Stop Signs:

  • These are used on private property (e.g., parking lots) to signal they’re not official government signs [12:39], a clever bit of legal and visual distinction.

• Design Legacy:

  • The classic stop sign's combination of shape, word, and color makes it nearly foolproof—even seen from the back, people recognize its message [13:28].

Notable Quote:

• [09:03] Kurt Kohlstedt (on the octagon as “danger” sign):

  “It sounds sort of occult almost. Right. But...the more sides a sign has, the higher the danger level it invokes.”

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3. Urbanism: The Miniature Golf Boom in the Great Depression

(Timestamps 14:09–20:40)

The Story

During the pandemic, Kurt researched how disasters change urban life, leading to a discovery: the explosion of miniature golf during the 1930s.

Insights

• Origins & Surge:

  • Mini golf, while not born in the Depression, exploded as city dwellers needed cheap, space-efficient recreation [15:18].
  • Entrepreneurs set up courses in vacant lots, rooftops, and even under billboards to save on lighting costs.

• Innovation Through Scarcity:

  • Scrappy course builders used whatever materials they could find—pipes, rocks, leftover turf—to devise creative, playable environments [17:43–18:39].
  • Some outlandish attractions: trained monkeys that stole golf balls!

• Social Insights:

  • Mini golf provided both an entrepreneurial opportunity and crucial distraction during a bleak economic era.
  • Its ubiquity and fun-loving culture stood in sharp contrast to the tough times.

Notable Quote:

• [17:24] Roman Mars:

  “I love picturing that, people just entrepreneurially setting up a miniature golf course, like a lemonade stand, like, everywhere they can.”

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4. Geography: A Perpetually Open U.S.-Canada Border Park

(Timestamps 20:40–27:26)

The Story

Kurt recounts the history and unique legal status of the Peace Arch Park, which straddles the Washington State and British Columbia border.

Insights

• Origins and Symbolism:

  • The Peace Arch, built in the early 1900s, bears the inscription "May these gates never be closed," referencing an 1812-era treaty guaranteeing an open border [21:24].

• Modern Realities:

  • For most of the past century, people could cross freely within the park's bounds [22:20].
  • During the COVID pandemic, the park became a critical meeting point for cross-border families, even enabling binational weddings despite travel restrictions [23:51].

• Legal Quirks:

  • Even amid strict border closures, the park remains open due to treaty obligations; neither country can close it without risking losing territory to the other [25:12].
  • “If Canada broke the treaty...the US could lay claim to parts of Ontario and Quebec. And if America broke it, Canada could get Parts of Maine, Michigan and Wisconsin.” —[26:08] Kurt Kohlstedt

• Local Concerns:

  • Some locals worry about health risks from visitors, but authorities can’t fully close it without breaching international law.

Notable Quote:

• [25:12] Roman Mars:

  “So this is the treaty that you mentioned, dating back to the War of 1812. I mean, that, that thing really has teeth. Like they have to keep the border open in some place.”

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5. Architecture: The White, Stepped Roofs of Bermuda

(Timestamps 27:26–34:12)

The Story

Through a listener lead from Bermuda, Kurt uncovers the ingenious design and resilience of the island’s unique white, stepped stone roofs.

Insights

• Hurricane-Ready:

  • After storms in the early 1700s devastated wood-framed buildings, Bermudians built heavy stone houses with steep, sloped roofs to resist hurricane forces [29:04–29:47].

• Water Collection:

  • The signature stair-step design slows rainwater, channeling it to gutters and allowing residents to collect potable water in large cisterns—crucial in a place without natural wells [30:34–31:23].

• Multi-purpose Innovation:

  • Roofs are coated with white lime, which both reflects sunlight and purifies the water [31:23].
  • Each home stores up to 40,000 gallons, ensuring self-sufficiency during storms or droughts.

• Aesthetic and Practical Brilliance:

  • The shimmering visual effect of the white roofs is a point of local pride.
  • Colin Campbell, Bermudian architect:

    “There should be no dark roofs in America. We should all be doing that. It’s just simple science.” [32:46]

• Global Applications:

  • The system is a model for sustainable, resilient design anywhere facing water scarcity or extreme weather.

Notable Quote:

• [33:21] Colin Campbell:

  “As a living human being, one wonders why we're here. I think in Bermuda you can almost figure it out. I'm that close sometimes.”

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6. Bonus Shorts: Conspicuous & Inconspicuous City Details

(Timestamps 36:25–41:22)

Trains → Diners

• The classic American diner mimics the layout and construction of train dining cars—long, narrow, and modular—often shipped like railcars to their final destinations. Their unique look is a legacy of efficient prefab design [37:19].

Hidden Wayfinding in Central Park

• The four-digit code on New York’s Central Park lampposts encodes location:
  • First two digits = nearest cross street
  • Last two digits: even = east side, odd = west side; lower = closer to the edge.
• It's a secret system for park employees…but now you know! [39:13–41:04]

Notable Quote:

• [41:04] Roman Mars:

  “Now that you know, you could…spin around with a blindfold on, set off in any direction, find a lamp and know where you are in Central park, which is pretty cool.”

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Memorable Quotes & Moments

• "[On stop sign shapes] The more sides a sign has, the higher the danger level it invokes. By the engineer’s reckoning, the circle…screamed danger and was recommended for railroad crossings." —[09:29] Roman Mars
• "What started us down this road was a letter from a fan." —[03:17] Kurt Kohlstedt (on the importance of listener ideas)
• "Mini golf becomes this kind of logical, infill solution in the urban environment, right?" —[15:18] Kurt Kohlstedt
• “[The Peace Arch park]…ends up being this kind of no man's land. And then when they leave, visitors just have to exit back to their country of origin.” —[22:45] Kurt Kohlstedt
• “It's Bermuda, it's family…Everything's two degrees of separation.” —[28:17–28:25] Colin Campbell

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Timestamps for Important Segments

• [01:02–03:15] : Introduction, book background, and episode format
• [03:17–13:52] : Infrastructure — Stop signs, their shapes, colors, and history
• [14:09–20:40] : Urbanism — Miniature golf’s Depression-era explosion
• [20:40–27:26] : Geography — Peace Arch Park and international border quirks
• [27:26–34:12] : Architecture — Bermuda’s water-harvesting, hurricane-proof roofs
• [36:25–38:51] : Conspicuous — How train cars inspired diner architecture
• [39:13–41:04] : Inconspicuous — Secret lamppost wayfinding system in Central Park

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Tone and Style

The episode maintains the classic 99% Invisible blend of curiosity, warmth, dry wit, and an appreciation for the quietly genius or delightfully odd designs shaping our world. Roman and Kurt’s interplay is both instructive and playful, continually inviting listeners to appreciate the stories woven into ordinary places and objects.

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Final Thoughts

Beyond the 99% Invisible City is a love letter to design’s unsung triumphs, urging listeners to “see” and appreciate the infrastructure, inventions, and hacks that quietly enhance daily life. Whether you’re a long-time fan or new to the show, this episode distills the series’ core appeal: storytelling that turns ordinary things into objects of wonder.

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For further exploration:

• Check out the original episodes highlighted by Kurt throughout the show: "Highways 101," "War, Famine, Pestilence and Design," "5440 or Fight," "99% Vernacular," "Train Sets," and the Mini Stories compilations ([41:22]).
• More details and links at 99pi.org.

Transcript

[Roman Mars]

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[Oregon Lottery Announcer]

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[Kurt Kohlstedt]

This is 99% invisible. I'm Curt Kohlstedt.

[Roman Mars]

Okay, so like, what I want you to do is I want you to take a breath. Take a breath, okay? And just like, you know, just get into your voice a little bit and go, this is 99% invisible. I'm Curt Kohlsted.

[Kurt Kohlstedt]

This is 99% invisible. I'm curt Kohlsted.

[Roman Mars]

Okay, no, no, no, no, no, no. I want you to do it again. I want you to do it again, okay? And I want you to do it now. This time. Like, I want you to do the gravitas is there. Like you're getting like that part of the tone. But I want you to add once. Now that you have that, I want you to add like a little bit of smile in your voice. Okay?

[Kurt Kohlstedt]

Okay.

[Roman Mars]

So you're gonna go, this is 99% invisible. I'm Curt Kohlsted.

[Kurt Kohlstedt]

This is 99% invisible. I'm curt Kohlsted.

[Roman Mars]

That's great. I love it. Print it.

[Kurt Kohlstedt]

In 2020, my co author Roman Mars and I put out a hit book about the built environment. It's an illustrated hardcover we called a field guide to the Hidden World of everyday design.

[Roman Mars]

The 99% Invisible City was an instant New York Times bestseller and topped the charts in the uk, Canada and Australia.

[Kurt Kohlstedt]

Versions of the book were also released in other countries as well. Translated into languages including Spanish, Czech, Chinese, Korean and Japanese.

[Roman Mars]

In the years since these first edition releases, Kurt and I have worked together on a number of new episodes and mini stories with an eye towards an eventual second edition, a kind of revised and expanded paperback. Iteration with additional as yet unprinted stories.

[Kurt Kohlstedt]

But today, rather than wait on publishers or printers, we've decided to share a set of four of our favorite short stories from the past half decade, each of which corresponds to one of the four main chapters of the 99% Invisible City.

[Roman Mars]

And those chapters are Infrastructure, Urbanism, Geography, and Architecture. So if you enjoy what follows, be sure to check out both the book, the 99% Invisible City, and the original episodes associated with each short story.

[Kurt Kohlstedt]

That's right. Let's get started.

[Roman Mars]

Infrastructure.

[Kurt Kohlstedt]

Shortly before the book came out, but after the final draft was already locked in, Roman and I did an episode on roadway signs and other roadway infrastructure designs. We titled it Highways 101. And what started us down this road was a letter from a fan.

[Roman Mars]

One of the things Kurt does is he checks our inbox for listener submitted ideas, combs through all of them. And earlier this summer, a 99pi fan named Daniel wrote us about a strange stop sign that he encountered while traveling. And you started digging into the story?

[Kurt Kohlstedt]

Yeah, so? So his email started like this. A couple of years ago, we took a trip to Hawaii, and my wife became obsessed over a few blue stop signs we saw in parking lots. The signs were the size and shape and used the same lettering as normal red stop signs, but they were bright blue.

[Roman Mars]

So I don't think I've ever seen that before.

[Kurt Kohlstedt]

I had never seen this either, either in images or in real life. So I started looking into why some were blue. And that turned out to be pretty easy to figure out. But it got me wondering something a lot more fundamental, which is, why are the rest of them all red? Right, exactly. Why is that such a thing in the first place?

[Roman Mars]

Totally.

[Kurt Kohlstedt]

Yeah. And that got me into, of course, digging into the whole history of stop signs. Of course.

[Roman Mars]

Of course. That's the only way this is going to go with you.

[Kurt Kohlstedt]

Yeah, it's just my nature. And as I was looking into this, this one figure kept popping up everywhere I looked. A guy named William Phelps Eno, who In the early 1900s became known as the father of traffic safety.

[Roman Mars]

Huh. Okay, so what do you have to do to earn that title? The father of traffic safety?

[Kurt Kohlstedt]

So Eno was born way back in the 1850s, and if you think about it, you know, 1850s, he's in New York. This is a New York without cars.

[Roman Mars]

Right.

[Kurt Kohlstedt]

So of course it's in New York without stop signs.

[Roman Mars]

Without stop signs, totally. Yeah. The roads back then were kind of this open space that was shared by carriages and pedestrians, and they moved all around it was a lot different.

[Kurt Kohlstedt]

Right, right. It wasn't very organized. More and more people were on the streets, and, you know, cars started showing up, and. And it just was increasingly clear that this was a mess and it was going to need some kind of regulation.

[Roman Mars]

And so was Eno some kind of road expert? Is that what he was working on?

[Kurt Kohlstedt]

Well, that's the thing. Not really. He came from this family real estate business, decided it wasn't for him, it wasn't his passion. His passion was traffic. So in 1900, he writes this article, and it's not entirely clear in hindsight if he realized what he was doing at the time, but he basically was writing a treatise that would lay the groundwork for everything he would do for the rest of his life. So in the end, he would come around to, you know, inventing and evolving all different kinds of traffic innovations, things we take for granted today, like road rejunctions and pedestrian crossings.

[Roman Mars]

Wow. So he really earned that title, the father of traffic safety. Absolutely.

[Kurt Kohlstedt]

And once his ideas got some traction in the US he began helping other cities create traffic plans. And some really recognizable designs trace back to him, like roundabouts at Piccadilly Circus in London and around the Arc de Triomphe in Paris. And he was even inducted into the Legion of Honor by the French government after World War I for traffic.

[Roman Mars]

Yes, he got that. Wow. And so was Eno the man who invented the stop sign?

[Kurt Kohlstedt]

Well, that's the thing. I kind of fell down this rabbit hole of looking into him. Well, one thing I realized along the way was that I was never going to find the inventor of the stop sign.

[Roman Mars]

Yeah.

[Kurt Kohlstedt]

Because it's one of those things that has existed in various forms for a while now. But it's safe to say that Eno played a really big role in popularizing stop signs and yield signs and that kind of signage infrastructure. And also, you know, put this in context, right? Stop signs back then, they weren't what we think of as stop signs today. Their designs varied from place to place. One of the first ones that popped up in Detroit in, I think it was 1915, had black lettering on a white background, presumably for contrast. So they really. They came in all these different shapes and sizes, and there was no sort of one person, you could say, aha, that guy made the stop sign.

[Roman Mars]

Yeah, I mean, I think that makes sense to me that there would be a need for stop signs, and therefore they would be invented in multiple places and multiple times. So when did they sort of get this octagonal shape that we attribute to them, like when did that happen?

[Kurt Kohlstedt]

Right. So that one actually does have a specific answer. And the answer is 1923. That's when the Mississippi Valley association of State Highway Departments decided to. To standardize the shape.

[Roman Mars]

That's a very specific answer.

[Kurt Kohlstedt]

That's great. And it was a pretty good idea to make it a non standard shape, something that would stand out. But there was actually more to it than that. They had this idea that they could create an association between geometry and safety.

[Roman Mars]

Explain more what you mean there.

[Kurt Kohlstedt]

Well, they believed that the shape itself could communicate something like part of what the sign was trying to do could be achieved through the shape of that sign.

[Roman Mars]

Okay, so we're not talking about just associating a rare shape with a specific meaning. They actually there's some kind of theory behind 8 having a meaning that ties to stopping.

[Kurt Kohlstedt]

Yes. And this was a huge surprise to.

[Roman Mars]

Me because it sounds like nonsense.

[Kurt Kohlstedt]

It sounds right. It sounds sort of occult almost. Right. But I found this out through this New York Times magazine article by Hillary Greenbaum and Dana Rubenstein. And I'm just going to have you read this excerpt for context. It explains why the Highway Departments association recommended different shapes for different signs.

[Roman Mars]

Okay, here it is. Quote, the recommendations were based on a simple, albeit not exactly intuitive idea. The more sides a sign has, the higher the danger level it invokes. By the engineer's reckoning, the circle, which has an infinite number of sides screamed danger and was recommended for railroad crossings. The octagon with its eight sides was used to denote the second highest level. The diamond shape was for warning signs. And the rectangle and square shapes were used for informational signs. That is just wild, right? I mean, there's so many things that I have, so many questions I have about this and one of which is like, it's a circle. Really have an infinite number of sides?

[Kurt Kohlstedt]

Well, yeah. So I'm thinking back to like, you know, grade school geometry and I'm like, I mean, I think that there's something to that. I think it's like, yeah, if you.

[Roman Mars]

Take the tangent of each point and therefore it has an infinite number of sides. But I don't think people perceive it as having infinite numbers. I think they perceive it as having one side.

[Kurt Kohlstedt]

Right. It's not like we look at a circle, a square and a triangle, triangle. And we say, aha, right, three, four and infinite. It never in a million years occurred to me that there was some grand geometric theory behind us stop sign shapes. But if you think about it, if you start to unpack it and you look at Signs around you, you can sort of understand what they're getting at. Right. It's like, well, yeah, rectangular signs often tell you, like, what exit to take or something. There's circles at railroad crossings. Sure, yeah.

[Roman Mars]

But there's also like arm bars at railroad crossings, you know, like, because the circle is not quite enough sometimes. There's also X's and arm bars and all kinds of other things. So I get that there's a theory behind it, and if it has some kind of basis in semiotics, I'm willing to entertain that notion. So now that, you know, in 1923 in Mississippi, they established the shape, how did they come up with the red background?

[Kurt Kohlstedt]

Well, that might seem like the simpler decision. That would actually took a while longer. At the time, yellow was often used in part just for material science reasons. Like they couldn't get a really good reflective, durable red. And so yellow showed up well at night. So for decades, that was the general standard. And then in the 1950s, they made red the official standard.

[Roman Mars]

Okay. So yellow, because you can make kind of a matte yellow and it contrasts really well with. With black, for example, and it looks really good at night. But until you get that shiny red that you see on a stop sign, red is not a very good stop sign color.

[Kurt Kohlstedt]

Right. And if you think about, like when you see a red stop sign at night, it is really shiny and really reflective. And also by. By that time too, you know, we've got stoplights and other signage, and red has really got this built up association of being a thing telling you to stop. So making them red just kind of fit with the grander scheme of everything else that was going on at the time.

[Roman Mars]

Yeah, and it's a warning color in nature. I suppose yellow is too, but yeah, it makes sense. So how does this get us to those blue stop signs and why? That Daniel found.

[Kurt Kohlstedt]

Oh, right. And that's how we come. Full circle, or full octagon, as it were. And it turns out the blue painted stop signs are actually exceptional on purpose. You usually find them on private property places like store parking lots. And the reason they're blue is so they won't be confused with other official government red signs.

[Roman Mars]

That makes sense. So they're like intentional fakes because they don't want it to seem like it's a sign maintained by the city or county. So they're like mall cops. They have a badge, they might have a gun, but they're not actual cops.

[Kurt Kohlstedt]

Yeah, right. Like whether you actually decide to pay attention to what the system sign's telling you is a little bit up to you, but it is really clear what it's trying to tell you, right?

[Roman Mars]

Yeah. I mean, that's one of the things I think that's so great about the stomp sign is that with the shape, the word stomp and the color, you can really take one or two of those elements and at this point it'll convey the meaning. Like, if you had a red octagon with no word stomp on it, I think people would generally stop.

[Kurt Kohlstedt]

Right. Or if you saw an octagon from behind, you'll know that that's a stop sign.

[Roman Mars]

The other people have to stop. Yeah, totally. Yeah. You know, that's a good sign. So they were onto something in Mississippi in 1923, and they figured something out. Urbanism.

[Kurt Kohlstedt]

During the COVID pandemic, I became interested in how other global disasters had historically impacted urban urban design. And my research yielded not only stories of white knuckled perseverance and resiliency, as you'd expect, but also tenacious creativity and playful innovation. So I pitched Roman on a Horseman of the Apocalypse themed episode titled War, Famine, Pestilence and Design. And that might all sound very serious, and a lot of it is, but. And that's when I came across the rise of miniature golf. During the Great Depression of all times.

[Roman Mars]

That is not an association I would have made. So when I picture miniature golf courses, I kind of think of the World War II era, like sort of kitschy leisure and baby boomers and that kind of thing. Not the Great Depression.

[Kurt Kohlstedt]

Yeah, right. I mean, the last thing on your mind when you look at a mini golf course is the worst economic crash in modern history.

[Roman Mars]

So did mini golf come up because, like, it was too expensive to maintain? You know, big fancy golf courses or something like that?

[Kurt Kohlstedt]

I mean, that's part of it, right? There's no way you're going to maintain these huge grounds for just a couple people walking along with their golf clubs. And like, all that we associate with sort of luxurious, sprawling golf courses. That was kind of not on the agenda financially. But also there's just the matter of space, right? You've got all these people who are in cities and need something to do and, you know, they don't have transportation to get out of cities. So mini golf becomes this kind of logical solution, kind of infill solution in the urban environment, right?

[Roman Mars]

So, like, along with everything else, real estate prices plunged and there's some space, and you might, you know, if you have a little bit of space, you can build you know, a miniature golf course.

[Kurt Kohlstedt]

Yeah, that's exactly it. The conditions were in some ways totally ideal in the wake of 1929 for exactly this kind of activity. And so, while technically mini golf actually predates the stock market collapse, the crisis really ramped up interest in it. And you have, as you noted, like, tons of closed businesses and vacant lots. And, you know, all of this is just ripe for entrepreneurs to take over. And even in places where there's not extra space, people just kind of made space. Like they would convert rooftops into pee wee golf courses or parking lots, really anything. And so it was this surprisingly huge fad. And at one point, somebody even called it the madness of the 1930s.

[Roman Mars]

Specifically, talking about miniature pee wee golf is the madness in this phrase.

[Kurt Kohlstedt]

Wow. Absolute insanity.

[Roman Mars]

That's quite the sequel to the roaring twenties.

[Kurt Kohlstedt]

Yeah. And so you've got these two very different periods, in a way. But there's also this parallel where, if you think about it, everybody needs recreation and distraction, and it doesn't matter if things are going well or they're going horribly. And given the economic situation in the 30s, cheaper activities were naturally much more appealing. So on the business side, it's also an opportunity. Right, because people could turn their own yards into courses or the interiors of their unused office buildings. Basically, anybody could try their hand at building a course. And so tons of people did.

[Roman Mars]

Wow. I love picturing that the people just entrepreneurially, like, setting up a miniature golf course, like a lemonade stand, like, everywhere they can. So when did all the things that I think of when it comes to miniature golf crop up? Like the, you know, the mechanical windmills or the ramps and, you know, all that sort of stuff. When did that happen?

[Kurt Kohlstedt]

So some of the more technologically advanced stuff came later. But a lot of those basic things that we still see in miniature golf courses today do date back to this exact era. Things like ramps and bridges and ridges, people just build out of, like, available dirt or whatever they could find. And at the same time, you have this recent invention of artificial turf, which helps courses hold up better to foot traffic. So people who could afford it would add that to make a more robust course. But, you know, really the kind of key in all this is all the odds and ends. Course makers could just grab whatever scraps they could find, pipes and stones, and just work them into this bigger design. And there was some scrappy entrepreneurialism in picking the sites for these places, too. Like, some would situate their courses underneath big lit up billboards so that they could operate at Night without having to pay for, you know, the light bulbs or the electricity.

[Roman Mars]

Oh, I love it. This is so fun to picture. Like, cities filled with miniature golf courses everywhere. I mean, am I getting this right? Is it really, like, like, everywhere?

[Kurt Kohlstedt]

Yeah, I mean, I've literally seen pictures of it being everywhere. And, like, I love these images of, like, little rooftops that are where people are crowded around, like, playing mini golf. And, you know, it's totally the opposite of what we can imagine today. Right. Like, you look at New York City and you think, well, every bit of real estate is used and expensive, but back then, it was like, no, there were. There were little spaces you could cram into, and so people would just head out in droves and go play mini golf.

[Roman Mars]

Wow. I mean, mini golf is delightful, so it doesn't surprise me all that much, but the ubiquity of it that you're describing really is striking.

[Kurt Kohlstedt]

Yeah. And of course, with all these creators vying to make their course the best course to try to attract more players, there was innovation around that too. Like, ways that people would try to set theirs apart. Things like pools and mazes and traps popped up, and eventually more kind of fancy things like fountains and forests and castles and even replicas of famous architecture like the Taj Mahal or the Great Wall of China. And so over time, these things become almost like tiny theme parks, right? Like, just populated with all kinds of wild and creative and colorful stuff. And this one in particular that I read about, I think has my personal favorite feature, which is a trained monkey that goes after your ball. So if you're not careful, it'll just come and snatch your ball, and it's like, game over.

[Roman Mars]

I would definitely go to that park.

[Kurt Kohlstedt]

Oh, yeah, Yeah. I wish that one was still around today. But a lot of the elements are still around, Right? Like those complex courses with the miniature architecture. It's, like, become a kind of staple. And it's still, like, this thing that we associate with, like, a fun family night out.

[Roman Mars]

Totally. It's just sort of fun to imagine New York City just being carpeted with miniature golf courses, of all things. I just. I kind of love it.

[Kurt Kohlstedt]

Oh, I do, too. I do too. Geography 99% invisible has a recurring episode series we call Map Quests. Each new installment collects geography related stories from different producers. In some cases, a given collection might revolve around a specific plan, place, or typology. And one Such set, named 5440 or fight, came out during the COVID era. And it contains a set of stories centered on the border between the United States and our country's affable neighbor to the north.

[Roman Mars]

And you have a Canadian border story for us?

[Kurt Kohlstedt]

Oh, I do.

[Roman Mars]

Okay, hit me.

[Kurt Kohlstedt]

It's about this pair of adjacent parks that are along the U.S. canadian border in Blaine, Washington, and Surrey, British Columbia. And in these parks, like, right where they meet along the border, there's this big peace arch monument with this inscription, may these gates never be closed.

[Roman Mars]

Wow. Well, that's a pretty bold statement for a border.

[Kurt Kohlstedt]

Right.

[Roman Mars]

Which seems like antithetical to what borders are usually about. So what's the story there?

[Kurt Kohlstedt]

Well, the arch and the parks date back to the early 1900s, but that never closed sentiment is actually a nod to the War of 1812 between the US and the UK and at the end of that conflict, basically, both sides signed a treaty to leave the border between the U.S. and Canada undefended as a sign of friendship.

[Roman Mars]

And so now there's this arch with this sentiment written on it. But, I mean, can you truly walk through it whenever you want?

[Kurt Kohlstedt]

Well, yeah, for most of the past century, you absolutely could. And when this park space is open for visitors, people can just freely cross into it from either side and then hang out without actually waiting to get through some tedious border checkpoint. So it ends up being this kind of no man's land. And then when they leave, visitors just have to exit back to their country of origin.

[Roman Mars]

Okay, so the arch doesn't really operate as a checkpoint, but it sounds as if the entrance to each park might operate as a checkpoint a little bit.

[Kurt Kohlstedt]

Well, sort of. It's like you can freely walk into the park, and there's people patrolling the park. But the real key is you should have identification with you, because when you try to exit the park, they want to make sure that you're coming back into the country you're supposed to be coming back into.

[Roman Mars]

Yeah. Okay, that makes sense. That makes sense. But it's a little less rigorous than what we think of as a normal international border checkpoint.

[Kurt Kohlstedt]

Oh, absolutely. Yeah. Yeah.

[Colin Campbell]

Cool.

[Kurt Kohlstedt]

But it started to change a little bit in this past year and a half, as you might imagine, because of the pandemic.

[Roman Mars]

Right?

[Kurt Kohlstedt]

Yeah. So each country maintains and controls its side of the park. Right. And early in the pandemic, both sides kept everything open. But even after Canada decided to close its side down, Canadians have still been able to meet up with Americans by crossing into the US park along this one side.

[Roman Mars]

Huh? Well, I could imagine a lot of people are taking advantage of that because everything else was pretty closed.

[Kurt Kohlstedt]

Oh, yeah, absolutely. Like a lot of friends and families split by the border have continued to gather here. And there have even been a ton of binational weddings at the park.

[Roman Mars]

Well, that makes sense. I mean, it's a convenient way to get together and people like to get married in parks.

[Kurt Kohlstedt]

Yeah, absolutely.

[Roman Mars]

I don't know what you do after the ceremony. You just split apart again.

[Kurt Kohlstedt]

Yeah. You go your separate ways. I mean, that's crazy thing, right? It's like you still have to kind of go back to your country of.

[Roman Mars]

Origin, but it, you know, it's still a pretty convenient place for people to get together and celebrate.

[Kurt Kohlstedt]

Yeah, it's partly that direct ease of access, but also people fully crossing over in conventional ways have faced up to a two week quarantine and COVID testing, but they can get around all that by meeting up in this spot instead. And as you might imagine, you know, divided families who can't afford to take all that time off of work to self isolate after a trip. I mean, this border zone loophole has been a real boon for them.

[Roman Mars]

I'm pretty careful about all the COVID stuff and I think that these quarantines are really, really effective. And I'm just kind of surprised that both countries just haven't shut this down entirely.

[Kurt Kohlstedt]

Yeah, and you know, that's kind of the craziest part, because legally, no matter what either country wants to do, neither side can fully close the border because that would be an international treaty violation.

[Roman Mars]

So this is the treaty that you mentioned, dating back to the War of 1812. I mean, that, that thing really has teeth. Like they have to keep the border open in some place.

[Kurt Kohlstedt]

Yep, that's the idea. And so you still have authorities policing the parks and, you know, regulating who is allowed in and where they exit, but they're not really able to just stop people from meeting up entirely.

[Roman Mars]

Huh, that's kind of amazing. So for the sake of argument, what would happen if one side actually decided to put up a wall and shut the border down? I mean, Canada was pretty proactive when it came to COVID protocols and shutting the border down. What would happen if they put their wall up?

[Kurt Kohlstedt]

Well, that's the thing. I was looking into this and I found this immigration lawyer who was interviewed by the cbc and he says that a full closure would have some pretty wild side effects and they would depend upon, like, which side violates the agreement.

[Roman Mars]

Okay.

[Kurt Kohlstedt]

So he claims if Canada broke the treaty, in theory, the US could lay claim to parts of Ontario and Quebec. And if America broke it, Canada could get Parts of Maine, Michigan and Wisconsin. So basically North American geography as we know it is contingent on this early 1800s treaty remaining in effect.

[Roman Mars]

This is just wild. But are people, you know, still kind of worried about meetups, you know, in this park during the pandemic anyway?

[Kurt Kohlstedt]

Yeah, no, they do take it really seriously. And there are locals, you know, on both sides who are concerned about COVID from all these visitors of course, which makes sense. And so a lot comes down to individual visitors and some of them play it really safe, right? They just sit on their side of the border in chairs and chat with people from the other side across the border. But whatever we think or the government thinks about it in terms of health and safety, it just kind of is what it is. Neither side can actually shut it down.

[Roman Mars]

Entirely, at least without trading parts of Ontario and Maine in the process.

[Colin Campbell]

Right.

[Kurt Kohlstedt]

Except for that. Yeah, except exactly.

[Roman Mars]

Architecture.

[Kurt Kohlstedt]

For our 500th episode we produced a three part series of stories on vernacular architecture. And my contribution to the set covered an ingenious regional roof design which I learned about from a fan of the show. A while back I opened an email from a 99pi listener located in Bermuda named Amy Daniels in which she introduced me to her island's remarkable vernacular architecture. So I wrote back to her to find out more and the next thing I knew Amy was introducing me to a local architect.

[Colin Campbell]

My name is Colin Campbell. I'm a Senior Architect for OBM in Bermuda. OBM is a firm that started in Bermuda over 85 years ago.

[Kurt Kohlstedt]

And when I asked Colin how he and Amy knew one another.

[Colin Campbell]

It's Bermuda, it's family. Amy asked her mother and her mother scratched her head, said oh, I know this fellow.

[Kurt Kohlstedt]

So everything's two degrees of separation.

[Colin Campbell]

Exactly, exactly.

[Kurt Kohlstedt]

Before we got to architecture, I asked Colin to start out by just telling me about Bermuda, which to be honest he really sold me on.

[Colin Campbell]

Bermuda is a place that if it hadn't been made you couldn't dream it up. It's so crazy beautiful. It's a Little island, it's 22 square miles, it's just on the edge of the Gulf Stream, so we have a temperate climate as opposed to a colder North Atlantic climate.

[Kurt Kohlstedt]

Colin went on to explain that the first European settlers arrived on this beautiful island back in the 1600s and a lot of their early buildings were wood framed. But as we all know from the Three Little Pigs, straw and wood aren't the most robust materials.

[Colin Campbell]

For almost 100 years people did a stick and frame construction and then after a couple of hurricanes in 1712, 17, 14, a light bulb went on, and the only thing left standing were stone buildings. And so the whole technology changed, and people started building with native stone.

[Kurt Kohlstedt]

And so stone became a critical part of the island's vernacular. It made for robust walls, and it made use of this plentiful local material. And these stone walls were in turn topped with heavy stone roofs, which have a noticeably steep slope, a slope which serves a vital function in a hurricane. It turns out that a shallow roof can really suck during a tropical storm, while a steep roof. Well, I'll just let Colin explain it.

[Colin Campbell]

It doesn't suffer suction, which is the big problem in a hurricane. As the wind goes rushing over a roof, if the roof has a lower pitch, it acts as a wing and you have lift. And many buildings are torn apart, not by the wind pushing it, but the suction forces that collect on the other side of the roof roof. So these slightly higher pitched roofs here in Bermuda also act to create enough turbulence that they break the suction forces and they stay intact.

[Kurt Kohlstedt]

So the roof pitch helps. But the most distinctive part of these rooftops visually isn't the slope. It's the way overlapping stone slats make the sides of each roof look like a bright white staircase. And this style of Bermuda roof serves a purpose related to another feature of the island's climate.

[Colin Campbell]

And what this does is it slows the water down as the water hits the roof. Instead of going rushing down on a flat plane surface, it has to go down a step.

[Kurt Kohlstedt]

So while the overall pitch of the roof is steep, that's offset by this staircase shape, which keeps water from running down and off the sides too quickly.

[Colin Campbell]

Almost like a little river going through pebbles and the like. So it slows the water down so you can capture the water at the gutter level and you're not losing it over the edge of the eaves.

[Kurt Kohlstedt]

Catching water has been an essential function of houses in Bermuda almost since the beginning.

[Colin Campbell]

And that was important because the homes did not have wells or any type of common water distribution systems. So we captured the rainwater for our potable water, and this got started in 1612 or thereabouts, just because there was insufficient water on the island, available through wells and the like.

[Kurt Kohlstedt]

Early settlers also came up with a clever way to top off these ruse. A coating of white lime. This bright finish helped keep houses cool by reflecting sunlight, while the lime helped purify incoming water. Of course, for this whole clever water collection system to work, it has to rain. Thankfully, the island's rainfall is generally pretty.

[Colin Campbell]

Consistent, but not always We've certainly seen in the last couple of years where you go two months or almost three months without any reasonable rainfall to help.

[Kurt Kohlstedt]

Hedge these dry spells. A typical Bermuda home can store an astonishing amount of water.

[Colin Campbell]

Houses today will carry anywhere from 12 to 40,000 gallons of water. Every house has its own water pump and pressure system. Why that's important, especially in a hurricane prone zone such as Bermuda, is that in the instance of a loss of power, you can still get fresh water because every house is self sustaining.

[Kurt Kohlstedt]

This combination of self sufficiency and the durability of local architecture helps the island bounce back incredibly fast from even major weather event.

[Colin Campbell]

We don't appear to suffer the amount of damage you see in some of the other islands and the coastal parts of the United States in the post hurricane event. In Bermuda, after a major event, the island has generally had lights on ready to go within 24 or 36 hours.

[Kurt Kohlstedt]

And that's all well and good for the residents of Bermuda, but Colin is rightfully insistent that these local solutions have global applications too.

[Colin Campbell]

The approach to conserve water and to use those resources again is going to be critical for the years going forward as a strategy for communities which are going to have seasonal droughts. And as we know, we're all going into a global warming condition. White roofs reflect heat. That makes sense. There should be no dark roofs in America. We should all be doing that. It's just simple science.

[Kurt Kohlstedt]

I couldn't agree more. Architects would do well to study tried and tested vernacular solutions like these. And not just from Bermuda, but from around the world.

[Colin Campbell]

At Bermuda, Roof is only white. Sometimes in the reflection of the sky, there's a luminosity that happens. So the roofs are not static white, they shimmer white. And it's the interplay of light and darkness on the roofs and in the architecture that I find the most satisfying of the whole lot. To see the subtleties. You have to stand and watch it for just a little bit and then you go, oh, oh, that's not nice. That's great. Living in an ocean environment, this little park in the middle of the great blue sea is spectacular. And as a living human being, one wonders why we're here. I think in Bermuda you can almost figure it out. I'm that close sometimes.

[Kurt Kohlstedt]

More from our unofficial 99% Invisible City expanded audio Edition after the break.

[Roman Mars]

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[Roman Mars]

At the Beginning of the 99% Invisible City book, Kurt and I included two short chapters meant to set the stage for the four main ones. The dubbed Conspicuous and Inconspicuous. These contain stories examining aspects of cities that are either so obvious or so subtle that we tend to overlook them. First up, conspicuous.

[Kurt Kohlstedt]

A few years ago I produced a piece titled Train Set, which, you guessed it was all about trains. And we had so much fun with that that we produced two more train themed episodes that expanded our scope to include train cars that are conspicuously static, not on rails, but permanent Embedded fixtures of our built environment. Attention passengers. Food service has now begun in the dining car.

[Roman Mars]

As a building type, diners are striking the long and thin with chrome accents and rounded corners. Inside their narrow spaces, there's just enough room to walk through and sit down. In a built world of taller and deeper structures made with stone and brick and steel and glass, diners are kind of strange. But if you understand where they come from, all their curious design features suddenly make a lot more sense. Diners are an evolution of dining cars. You know, the ones found on trains. It's not just their name and aesthetic that traces back to railways. Many diners were prefaced fabricated as modular units and specifically designed to be taken by truck or train to their final destination. Hence the long and narrow layout. Entrepreneur Jerry o' Mahoney is widely credited with coming up with the diner as it is and building the first one in 1913. His creations evolved to have that now distinctive diner look. Long and narrow, sleek and curvy, with flashy chrome accents. Many vintage prefab diners came complete with counters, stools, tile floors, even restrooms. And they were just transported to the destination and they got hooked up to on site utilities. In some cases, actual dining cars were also converted into freestanding diners. And in other cases, diners are simply made to look like classic prefabs for that nostalgic appeal, which, by the way, totally works on me.

[Kurt Kohlstedt]

Finally, as you probably know, we have an annual tradition here at 99% invisible. At the end of the year, we gather up short mini stories from various producers. And some of these stories are shorter than others, like this one. A sweet and simple little solo about an inconspicuous wayfinding system in New York City's Central Park.

[Roman Mars]

One of the stories that came over the transom via Twitter this year is about the four digit codes on the lampposts in Central park in New York City. So each lamppost in the park has a four digit number on it. The first two digits represent the closest cross street to the post in the 840 acre city park. So if the first two digits are 96, the post is parallel to 96th Street. The second two digits represent two things. Which side the lamppost is on and its relative distance from the edge. If it is an even number, then it's on the east side of the park. So E, even E east. That's how I remember that. And an odd number means that that light is closer to the west side. The smaller the number, the closer it is to the edge. So for example, 9605 is roughly parallel to 96th street, and it's pretty close to the west side because it has a small OD. But if a lamppost is numbered 9642, it's closer to the east side than it is the west side. But because it has that high number of 42, it's more towards the middle of the park. So if you ever get lost in Central park, find a lamppost, read the embossed number, and you'll know roughly where you are. When the explanation for this code, you know, found people on the Internet, a lot of people were intrigued by it, but they often wondered, well, what good is this cool wayfinding method? And if nobody knows about it? Well, the answer is it's not really wayfinding for us, for patrons of the park. It's really for park employees whose job it is to replace and repair those lamps. Now that you know, you could, like, spin around with a blindfold on, set off in any direction, find a lamp and know where you are in Central park, which is pretty cool.

[Kurt Kohlstedt]

And if you love little design stories like that, you're going to find a lot more when you page through your copy of the 99% Invisible City or Listen to the audiobook narrated by our very own Roman Mars. So head to 99pi.orgbook and pick up your preferred format.

[Roman Mars]

Meanwhile, for more 99pi stories like those you heard today, be sure to check out the full episodes that Kurt mentioned, starting with highways 101, then war, famine, pestilence and design, followed by 5000, 440 or fight, as well as 99% vernacular and train sets, and finally, our annual Mini Stories volumes, which you cannot miss because we're right in the middle of them right now. You can find links to all those aforementioned episodes in this week's web companion at 99pi.org.

[Kurt Kohlstedt]

99% invisible was produced this week by Roman Mars and me, Kurt Kolsted, mix by Martin Gonzalez and music by Swan Real. Roman Mars is our host. Kathy Tu is our executive producer. Delaney hall is our senior editor. The rest of the team includes Chris Berube, Jason De Leon, Emmett Fitzgerald, Christopher Johnson, Vivian Leigh Lasha, Madonn Joe Rosenberg, Kelly Prime, Jacob Medina, Gleason Talon and Rayne Stradley, and me, Kurt Kolstead. The 99% invisible logo was created by Stefan Lawrence. We are part of the SiriusXM podcast family now, headquartered six blocks north in the Pandora building in beautiful uptown Oakland, California. You can find us on all the usual social media sites, as well as our new Discord server. There's a link to that, as well as every past episode of [e-mail].

[Roman Mars]

Hello beautiful nerds, it's Roman here. If you're loving 99% invisible and you want to hear new episodes ad free and get access to exclusive bonus content, subscribe to SiriusXM Podcast plus on Apple Podcasts or visit siriusxm.com podcastplus to start your free trial today.