Backpackers come to this strip from all over the world for the dope or the prostitutes, or to make cut-rate arrangements to get somewhere else. Scrubby guest houses and cheap massage parlors cram the place, and narrow alleys spike off this road, where discount travel booths peddle no-fuss arrangements to Angkor Wat and Kathmandu and Phnom Penh—perennial must-sees on the backpacker circuit. Among the trips for hire along Khao San are a Good Morning, Vietnam tour (the movie was filmed in Bangkok and on the island of Phuket) and several Emmanuelle tours, featuring the French soft-core classic acted for real in Bangkok's infamous Patpong district. The film allusions allow for a type of sellers' shorthand, sketching the experience and lending richer visuals than a crude brochure.

Shortly before I arrived on Khao San Road, a small travel company called Sunshine Travel began offering a Beach tour. It was simply a trip to the remote but somewhat well known island of Phi Phi Lay, no different from the one offered last season or the season before that. But Hollywood had altered the worth of the small island, and increased its marketability.

What is there to see? I had asked the girl in the Sunshine booth, which was no more than a cart wheeled onto the puddle-clogged lane, two wheezing dogs slumbering underneath.

"Very nice beach, bird's nest cave, good snorkeling," she answered. She was about 19 years old and had long and wickedly curved fingernails on her left hand only, painted gold.

And the movie?

"Oh, yes, very good movie," she said, as if she had seen it already. We talked money, even though I wasn't planning to use a tour to get to the island, and I thanked her and left.

Next morning, under the bright sun, the street seemed less exotic and far shabbier. The tang of the city came in a rush, a mix of rot and sweet and smog that burned my nose. Before I headed south to the islands, I wanted to gauge the heat of an ongoing controversy surrounding the filming of The Beach, so I spent the morning at the Hello Internet Café, reading back issues of the Bangkok Post and the South China Post and the various Web sites that had sprung up to either flack the film or claim outrage at the destruction it had allegedly caused on Phi Phi Lay.

One activist, a 39-year-old Bangkok-based filmmaker named Ing Kanjanavanit, appeared frequently, frantic about the way Twentieth Century Fox was mistreating her country. Fox was, for instance, planting 60 additional palm trees on Maya Beach for the benefit of the cameras, and bulldozing sand to widen the strip, and temporarily uprooting native spider lilies and grasses. More than once she burst into tears of frustration before the reporters, her sobs placed into the record as she wailed about the ineffectualness of her efforts and the thickening corruption of her nation.

"Everything in this country is for sale," she told one reporter, suggesting that the $100,000 fee that Fox was paying to film on the island was pure payoff. "This affair of The Beach is like a mirror. It shows me what sort of country I'm living in." In the preceding months Ing and her allies had petitioned the U.S. Department of Justice to halt the filming, citing the Foreign Corrupt Practices Act, and she oversaw the marshaling of 39 Thai law professors in a petition to the Thai government, which successfully called for Fox to post a larger security bond prior to filming.

On the Web, small factions of pro-film and anti-film advocates did battle, the latter calling for boycotts of the movie and public rallies and heated debate on the serious environmental issues, while the former relied heavily on the yumminess of Leonardo DiCaprio for its ammunition. And in fact, had the extraordinarily popular DiCaprio not been involved in The Beach, it's likely the production would have passed through Thailand with barely a ripple. Phi Phi Lay, after all, was not even a cinematic virgin: Cutthroat Island, an unfortunate film starring Geena Davis and Matthew Modine as pirates, was filmed on Maya Beach in 1995; not a protester was to be found. But as any agent can tell you, Matthew Modine is not Leonardo DiCaprio.

From the computer at the Hello Internet Café I noted the charges leveled by environmentalists and the defenses offered by Fox and the film's director and DiCaprio himself. ("I would never be part of any project that did anything to harm nature," the star declared in a statement last January.) The sites were entertaining. There were photos of a serenely desolate Maya Beach in the weeks before the production, and blurred telephoto shots of the actors at work, and plenty of good gossip: Leo passes out from jellyfish bites; Leo impregnates his teenage costar; Leo requires a $45,000 mobile home to be shipped in from Britain; Leo looks fat.

The movie was re-creating a journey from a novel that I also was attempting to re-create, in part because I wanted to see what became of places that happened to slip, usually by chance, into popular culture. In his novel, Alex Garland has Richard start his journey on the Khao San Road. There he meets a Scottish backpacker who, prior to killing himself, gives Richard a map showing a necklace of small islands far to the south of Bangkok, near the popular tourist destination of Ko Samui on the eastern side of the long Thai peninsula. Rumors of a beach—unspoiled, idyllic, peopled with a small and happy community of expats—had been buzzing along the backpacking circuit, and Richard decides that this map is evidence of such a place. Armed with the map, Richard and a young French couple he has met (she: slender brunette, winning eyes, partial to toplessness; he: undeserving) set off to find the beach. The three move from Bangkok to Ko Samui, and from there to a smaller island, and finally to a smaller island still, where they find the beach. Richard and friends are accepted into this beach society, and several pleasant months follow—the expat islanders fishing and gardening for sustenance, smoking dope and playing soccer for recreation. But Garland infects Richard with Vietnam War fantasies, and these, coupled with the presence of armed Thai marijuana farmers on the island, slowly ratchet up the tension until the place erupts in an orgy of bloodletting, triggered by the arrival of several more backpackers on the beach—a not altogether subtle suggestion of the effects of tourism.

As it happens, Phi Phi Lay, which is located on the western side of the Thai peninsula, is never mentioned in the book. Garland based his fictional island on one he knew from the Philippines and then sited it in Thailand's Phangnga Bay. But this is a distinction that will soon be lost, since the film effectively trumps Garland's novel. The Beach is forever now on Phi Phi Lay.

There, there, that's me at Devil's Tower, in Wyoming, the butte from Close Encounters of the Third Kind, and me on the Chattooga River in Georgia, the one from Deliverance, and that's me with Blue Lagoon Cruises in Fiji on Nanuia Lailai Island, next to where they filmed The Blue Lagoon, which is Turtle Island, and you can visit that too...