The past is etched into the dusty cobblestoned streets of this seaside town. Donkey carts still rattle along, though stiff competition comes from the Ford pickup. Fishermen hawk red snapper in the streets every morning. Women wash clothes in the Cuale River, which bisects the town on its march from the mountains to the Pacific. Bells of the town cathedral call its people to noon mass.

Still, the tremors are unmistakable. A high-rise Sheraton is sprouting on the north shore, joining other resorts north and south of town. An office building and shopping mall are springing up near the sleepy town square. Cruise ships call with increasing frequency.

This once-quiet fishing village threatens to explode into the Mexican resort of the 1980s with an ear-piercing "ole!" And all because of what there is to do here -- which is nothing at all.

Nothing, that is, except have glorious fun in the sun as it awakens over the green velvet Sierra Madres, arcs across the sky and sinks as a fiery orange ball into the serene Pacific. Clearly, this is paradise about to happen.

"Isn't this great?" chirped Ruth, a stewardess with CP Air, who was frying on Playa del Sol, the uncluttered main beach a few steps south of town, as a parasailer drifted overhead.

"Nothing to do," is stealing gringos from other resorts with the swiftness of a Pancho Villa attack. Californians, Canadians and Europeans, especially, have flocked like lemmings in recent years.

Ruth sums up why. Mexico City is too kinetic, she says, and Acapulco is oversexed and crowded. And computerized cities like Cancun are a turnoff.

"Nobody bugs you here. It's less crowded and touristy. You won't tell anybody, will you?"

There is still an undiscovered air about the place. Shopping is nothing exceptional, so most of the action centers above, in front of, and on the beach.

Not that there aren't any ways to while away the hours. Parasailing is the rage. For 270 pesos (about $10) you are lifted by motorboat off the beach in a colorful parachute, drifting like a gull over 25-mile-wide Bahia de Banderas, five times larger than the bay at Acapulco. Touching back down on terra firma is the most depressing part.

For fisherman, the bay waters are thick with snapper, tuna, marlin and sailfish. There are charter expeditions, or you can rent a boat. Sailboats, speedboats -- even skis and surfboards -- are rentable.

How about horseback riding along the beach, like they do in the cigarette commercials? Your steed is 45 pesos an hour at Senorita's Rent-A-Horse. Sloshing along the fringe of the ocean is manna for any winter-weary body. Horses are corralled near the Playa de Oro and Posada Vallarata resorts, north of town.

There's also a guided horseback ride into the jungle (guidebooks tout a three-hour jeep safari, but it doesn't exist). Scuba diving and snorkeling are best south of town, where the beaches are whiter and the water cleaner.

A winding coastal road leads past secluded beaches (all government-owned, so enjoy) to the village of Mismaloya, a mecca for the snorkel and scuba crowd and, for landlubbers, the place to look for sea turtles. Mismaloya is what put Vallarta on the map, for better or worse (locals claim worse).

The year was 1962. Vallarta had one phone and a few thousand townfolk, most making their living by the sea. That's when "Night of the Iguana" was filmed here on a finger of jungle back from the beach. Underbrush has pretty much smothered the tile-roofed buildings used the film, but the restaurant built for Richard Burton and the rest of the cast still operates.

Burton and Liz Taylor still maintain separate casas in Vallarta, connected by a garlanded trellis above a cobblestoned road that rises steeply up the mountains. This patch of foreigner-owned homes is known to locals as "Gringo Gulch." Burton's is the best-known face in town, but other celebrities like Paul McCartney and Farrah Fawcett escape here to avoid the hassles of the heavyweight resorts.

The town is mostly an amalgam of red tile-roofed houses and buildings that start at the seawall and sweep only a few blocks to the foot of the mountains. A cathedral is the centerpiece of town, population 70,000.

It's a bone-jarring ride on the cobblestones. Volkswagen beetles are the main get-around, but jeeps and jalopies are plentiful. Traffic is a din. Town fathers installed a traffic light a few years back, but removed it when drivers ignored it. Street curbs are steep due to the rainy season, from late June to early October.

Eating is an anomaly. Americans who come here for good, eye-watering Mexican food are denied the chance. Best to avoid the local places for health reasons, they are told. Food and drink are to be taken at the resort hotels or better restaurants. But you'll find their menus mostly bereft of Mexican food. The pinheads think they're pleasing American appetites that way.

One happy exception is El Set, an open-air, four-tiered restaurant crowning a seaside cliff. A tree grows right through the roof. There are caged birds and animals and this rough-hewn place would be right at home in a tropical rain forest. So named because several movies were filmed in the area, El Set commands an uncluttered view of the Pacific. Happy hour is just that: sipping pinas coladas on the patio with someone special as the sun drops into the Pacific.

Visitors can put up at the charming inns intown or find good quality at the beach resorts north and south.

Posada Vallarta is a hacienda-style spa with pool, tennis and social programs, like a Saturday night fiesta. The pool area is ringed by pleasant gardens. Condos also rent for about $120 a day. Posada's Mexican omelette is a good way to jump-start your heart every morning.

Playa de Oro, down the street, is a closer-knit place, with a tangle of trees, bridges and pools for its epicenter. The second-level bar serves up exciting views of the ocean over the tips of the beach huts.

Posh Camino Real, south of town, requires a seven-night stay during the winter season. Whether you stay there or not, belly up to the swimming pool bar, savor some exotic drink from a coconut and guess what the wind chill factor is back home.

Taxis are plentiful and charge reasonable flat fees. For more ambitious types, jeeps rent for $32 a day with the first 200 kilometers free. Gas is (brace yourself) 65 cents a gallon.

Money: Exchange at a bank. The local ones close at 1:30 p.m., or earlier if they feel like it. One dollar fetches about 22 pesos.

Customs: Returning U.S. residents can bring home $300 worth of purchases, duty-free. Bring your passport.

Moctezuma's Revenge: It can spoil any vacation, so best to avoid the water of food sold from street carts. The larger hotels provide bottled water. You may wish to have your doctor prescribe medication before you go.

(In late December and early January, two groups of Americans visiting Puerto Vallarta suffered from diarrhea with "attack rates of 83 and 94 percent," according to the Center for Disease Contol (CDC) in Atlanta. A phone survey of 45 additional tourists returning to the United States around the end of January "revealed an attack rate of 69 percent." Last month health authorities in Puerto Vallarta were testing the city's water supply and bottled water, the CDC reported, but had found "no evidence . . . of contamination."

(The CDC has advised travelers to Puerto Vallarta "to eat only cooked food that is still hot and fruit that they peel themselves and to drink only the following: water that has been boiled or adequately disinfected with iodine or chlorine compounds, bottled carbonated water, soft drinks, beer or wine. Unpasteurized milk and milk products and beverages containing ice should be avoided.")