SWIMCITY, U.S.A.—The climate of SwimCity is humid subtropical, with temperatures hovering around an equatorial 78 degrees between the hours of 11 a.m. and 6 p.m. It is a small city, boasting about 60 full-time residents, though quadruple this number in tourists and drifters clog its thoroughfares at any given time, giving it a bustling feel. SwimCity has no post office, no church, and no jail, though it is not devoid of punishment. The official currency of SwimCity, if it has one, is survey feedback. It has one restaurant, which serves hamburgers. The entire municipality is contained within an enormous tent, more longhouse than circus big top, but made of clear plastic. Geographically, it is located firmly within the bounds of New York State, though it operates as an independent entity. Its main export appears to be walls.

I have been plopped down in the middle of Manhattan's Herald Square, inside a Sports Illustrated Hooverville, for the sole purpose of gawking openly at my favorite supermodels, though I will also accept two Old Spice Fresher Collection Timber Body Washes and a bandana in a color of my choosing (to be revealed later). Laborers working on behalf of the magazine recently constructed the temporary swim-themed town for the first in a set of twin events dubbed "the first-ever SI Swimsuit Fan Festival," tied to the release of this year's eponymous Swimsuit Issue. Tomorrow it will move to Nashville, where it will be re-incorporated as "SwimVille" for 48 hours, and then cease to exist.

It's 11:15 a.m., and a sticky warm front composed of hundreds of New Balance-wearing adult human males is headed toward the town square.

I'm one of a handful of women who is not a wearing a crop top and five-inch heels. Everything in SwimCity is free and open to the public, which immediately alarms me.

Although it was founded on the breezy idea that city should be swim, SwimCity is not a free-for-all vacation destination, zoned for the pursuit of happiness. It is a regimented, horny hell. The most famous models like Twitter phenom Chrissy Teigen and Real Housewives daughter Gigi Hadid are sequestered from visitors by stages and roped-off lines. Lesser-known swimsuit gals pose for photos on the floor with the men who have come to see them in the middle of a work day. Gray-suited bodyguards flank them, sometimes correcting visitor behavior. No hands! Don't lean! Move it along!

It is a real bummer town.

Before I am permitted to transverse the clear plastic border that separates SwimCity from the rest of the United States, my bag is inspected by no fewer than three male guards. Dozens of jumbo posters depicting models in various states of swimsuited undress hang dramatically from the sky, providing each new visitor with a good, angled look at a well-groomed, barely-concealed larger-than-life crotch. A man wearing a tuxedo vest offers me a gray-looking slider from SwimCity's sole dining establishment, which is a cardboard, Route 66-inspired diner, complete with one Tiffany blue booth seat and a shiny, silver table. I decline.

SwimCity's residents include about two dozen Sports Illustrated t-shirt-wearing male and female day laborers, who function as its traffic cops, directing the crowds and mediating minor offenses. There are the same number of male bodyguards for half the number of models.

At 11:15 a.m. when I arrive, the visitors are almost exclusively male. They range in age from late teens to late seventies, and very few of them are wearing what might be deemed "work slacks." Throughout the day, I spot four nylon Knicks backpacks and one Yankees sweatshirt, which bears a large grease stain. Many of the men are wearing genuine Hawaiian leis—"from Oregon," I am told—that are being passed out, for free, at a tropical display. Nearly everyone is holding an iPhone, tapping their screens to snap photos ad infinitum.

At lunchtime, a moderate number of female tourists join the mix. Some of them are teenaged girls accompanied by their mothers. Some of them do not appear to know where they are. I spot three babies during the course of the day, but I do not think SwimCity is a good place to bring your baby.

The mayor of SwimCity, if it has one, is surely the gray-haired man who sits in the only chair available to visitors for the entire duration of my visit.

For a town with no standalone structures, there is a suspiciously high number of walls in SwimCity. Within its tented borders stand an Old Spice wall, a Tennessee Farmland wall, a Hawaiian Surf wall (with sand floor), two Route 66 Diner walls, and a Body Paint wall. The last of these, much like the Berlin Wall prior to its collapse, is covered in colorful graffiti and tags. Visitors are allowed and encouraged to take photos of themselves in front of the walls, but traffic cops herd everyone into lines first.

The first wall I visit is located in the Old Spice district of SwimCity, where an animated blond model poses with a parade of men of various ages in front of the Old Spice wall. She puts her arms around each one, giggling and dancing to "Superstition," which the official SwimCity band is playing at a breakneck clip. Her taut, tan torso peeks out between her periwinkle blue crop top and matching high-waisted pencil skirt. I ask a traffic cop handing out samples of Old Spice body wash near the wall if he knows who she is, and he says, "nah."

A clean-cut, J. Crew t-shirt-wearing man to my left does. "That's her," he says, pointing up at the poster of Kelly Rohrbach hanging directly above my head. I look up at her belly button on the poster and then back at her face in real life. "Cool," I say. I am dazzled that her beauty in print transfers so seamlessly into flesh and bone.

I ask the man if he lives in New York City, and he says yes. "So you took off work for this?" I ask. He tells me that he is a professional dog walker and had "a little break in my schedule." I ask his friend, a red-haired man wearing track pants, if he's taken any photos with the models.

"I tried earlier," he tells me. "But the bodyguard kept saying 'No hands! No hands!' But then I look at this girl and she's hanging all over the guys. She's loving it."

I was not able to confirm whether or not she was loving it.

Swimming through the city, I feel like an anchovy being buffeted about in the vast ocean. At 5'2, I am seven inches shorter than the average American man, and this tent is packed full of them. At least six different times, I find myself in line for things I didn't even know I was in line for, because fog of visitors is so dense that my visibility is limited to the three feet directly in front of me. In one of these instances of serendipity, I end up in a line to have my Sports Illustrated Swimsuit Edition signed by two models. This is my first direct interaction with the living gods of SwimCity, and I am nervous.

I approach to the table and hand my magazine—purchased the night before for research purposes—to the mononymous Solveig, a strong-browed brunette. Solveig looks slightly confused by both my gender and the fact that I am backpacking through her city alone, but she signs her bare breasts on the page all the same, even adding "To Allie," a heart, and "xoxo." XOXO to you, Solveig. I slide down the table to the second model, feeling confident. I am thrilled to realize I recognize her right away.

"Oh, you're the cover girl!" I screech, wildly smiling.

She looks down like she is going to absolutely scream.

She is not the cover girl.

"I mean, you're all so beautiful!" I offer to her silence.

She gives me a "hah" and hands me back my magazine (signed with "xx" kisses but no hugs).

In SwimCity, unlike anywhere else on Earth, mistaking someone for the model on the cover of Sports Illustrated's Swimsuit Edition is one of the rudest things a person can do.

While everything in SwimCity is technically free, a pound of flesh is still exacted in exchange for body painting and bandanas. In order to get my body painted in front of the Berlin Body Paint Wall, a female SwimCity traffic cop informs me that I must sign it. She also tells me that I should take a photo with the model standing in front of the wall, whose name is Hailey.

After we take the photo, a male traffic cop shoves a bright green pen into my hand. "You have to sign the wall before you get painted," he says, repeating his coworker's command. I do. A frantic "Allie!"

Finally, I sit down in the designated body painting chair, where another female traffic cop shows me a variety of temporary tattoos from which I can select one design. I do not voice my disappointment that temporary tattoos are not the same thing as body paint, and pick a gold bracelet-style tattoo. I guess it looks like a bracelet, in the same way that a bright blue splash of color painted over a nipple looks like a bikini top. While she applies it, I ask her what SwimCity plans to do with the Body Paint wall.

"Oh we're just having everyone sign it," she says.

"I know," I say. "I mean after." Tomorrow, when SwimCity is a distant memory in the lives of Old New Yorkers; when my gold bracelet tattoo begins to fade.

"I don't know," she replies.

A short while later, I'm approached by another female traffic cop who asks me if I want an official SwimCity bandana. I say yes, and she informs me that before she can give it to me, I must take a survey on an iPad.

The survey is about the brands displaying their wares in SwimCity. Am I aware of Old Spice? she asks. Schick? Lexus? I say yes, yes, yes. The survey, which is several pages long, grows tiresome, and eventually she just fills in the answers for me, click click click. I notice that she answers that I am aware of the brand Maui Jim, but I was not and am not aware of the brand Maui Jim.

The bandana I pick is: baby blue.

SwimCity has allocated no municipal funds for an official prison within its borders. I expect misbehaving guests are simply asked to leave. Models, however, can apparently run afoul of some unknown higher power ( Sports Illustrated?) and thereby be forced pay a penalty, which is playing Connect Four with jittery visitors for endless stretches of time.

The Connect Four game is located in the cardboard Route 66 diner. The models sit on the blue booth seat, facing a line of male visitors—a line that, to them, must look unending—who come bearing nothing but their own faltering attempts at conversation and a pronounced eagerness to stare at a human woman for two to three minutes.

Wishing to observe this practice more closely, I hop in line behind six men who are waiting to play Connect Four with the unlucky Sara Sampaio. I was not able to confirm whether or not she was loving it.

Shortly after I get in line, a female SwimCity employee approaches us and asks, "Does everybody know what they're in line for?" The middle-aged male in front of me, who possibly does not speak English, does not. He leaves.

The traffic cop then asks the three younger men who've lined up behind me to leave as well, since Sara will get a break from her punishment soon. "There are plenty of other girls for you to see," notes madame.

With luscious heaps of dark brown hair and large pale green eyes, the willowy Sampaio is easily the most beautiful woman I see all day. When it's finally my turn to play, I compliment her red polish manicure and ask her how long she's been playing. "Too many games," she says in a sad Portuguese accent. "I played yesterday, too." I feel bad for her. This is not why 23-year-old women cross oceans—to work in the Connect Four factories of fake cities. Lost in private reverie, I become distracted from the game at hand. I realize too late that I've—almost immediately—set Sara up with the perfect diagonal win.

"It's okay!!!" I say, when she realizes it, several (like...20) seconds later.

She stands up automatically to pose for a photo.

"Nice meeting you," she says after the shutter clicks.

I expect a guard to usher Sara away for a moment of peace, but as I turn to leave, she sits back down. I realize that this is because the traffic cop has begrudgingly allowed one more pleading visitor to get in line to play Connect Four: a tall, thin woman wearing a snakeskin-printed crop top and five-inch stilettos, which is a louder approximation of the outfit Sara picked for the day. A couple hours earlier, I overheard this visitor telling a male companion that she "basically knows" Chrissy Teigen through a girl her half-brother is dating in Texas. Today is the day she is going to really know each and every one of the Sports Illustrated swimsuit models, because she's going to get discovered and become one of them, right here in SwimCity.

She takes swift, sure steps toward the drained Sara, right hand extended. "Hiiiii!" she exclaims, eyes gleaming. I think she wouldn't mind playing Connect Four all day if she had to.

I return to New York.

Photos by Allie Jones