(Coastal Living) -- For years, seasoned travelers have touted the 150 miles of verdant Pacific coast from Puerto Vallarta south to Manzanillo as Mexico's undiscovered treasure.Remarkably, Costa Alegre, or Happy Coast, still is, despite a roster of visitors that includes A-list actors and directors, European aristocrats, Sports Illustrated swimsuit models and globe-trotting polo players.The mystique persists because Costa Alegre has preserved its natural beauty, and because its remoteness keeps the paparazzi and other modern irritants at bay. "It's just isolated enough to discourage the package tourists and spring-break hordes," says Giorgio Brignone, a member of the Italian clan that has smartly developed the stretch known as Costa Careyes. "We've always had a lot of European visitors, but now we're getting more Americans who realize it's not difficult to travel here." Frequent flights connect the United States to Puerto Vallarta and Manzanillo, and on the well-paved highway between them, traffic flows freely. Except, that is, for the occasional cattle drive (imagine the Pacific Coast Highway doubling as the Chisholm Trail) or party of pint-size banditos (kids blocking the road to solicit donations for school).A trio of alluring resorts -- El Careyes, Las Alamandas, and El Tamarindo -- dots a south-central section of Costa Alegre that takes little more than an hour to drive, making it feasible to stay at any or all on one trip. Each follows the example set by Giorgio's father, Gian Franco Brignone, who arrived in Careyes in the late '60s: Start with hundreds of acres of unspoiled coast; insist on careful, low-density development; and build in a style that harmonizes with nature. All three resorts offer ways to explore the lush tropical environment, spa services, varied menus that draw on fresh fish and other local ingredients, and mucho romantic atmosphere.And all draw design inspiration from the cliff-topping Careyes villas, which blend vibrant walls, patterned concrete floors, and open-sided living areas crowned with soaring thatched roofs. The style is at once contemporary, timeless, and comfortable. Visitors can rent these fabulous villas or simply admire them while staying at El Careyes Beach Resort or in the colorful casitas above neighboring Playa Rosa.El Careyes Beach ResortPainted sunset hues, the resort resembles a whimsical Mediterranean village wrapped around a palm-studded piazza. Beyond its sprawling, amoeba-shape pool lies a crescent of sand and offshore islets so picturesque that "guests sometimes compliment us for their placement," notes a waiter in the open-air dining room. The cosmopolitan crowd that comes here in the fall-to-spring high season circulates at multilingual parties in the villas, at resort restaurants, and at simple eateries along the highway.Las AlamandasTo the north, with 1,500 gloriously empty acres and a maximum capacity of 30 guests, Las Alamandas encourages guests to indulge their whims. Care to canter on a deserted beach? Your horse awaits. Fancy a candlelit dinner for two on a seaside promontory? �No problema! Owner Isabel Goldsmith created this hedonistic hacienda to her own exacting standards and welcomes visitors personally. The comfortable, color-splashed rooms feature private patios, Mexican crafts, and ample soaking tubs. The main dining area overlooks the ocean, beach, whiskery palms, and, at dusk, foraging tejones. Mexico's answer to raccoons, these creatures provide a sort of floor show as they roam to and fro, their long, curving tails gliding through the air like question marks. The bar's signature rum punch shares its name with one of the property's beaches: Soledad. The same word -- Spanish for solitude -- sums up much of the appeal of Las Alamandas, a perfect place to be alone together.El TamarindoMarrying palapa roofs, outdoor lounge areas, plunge pools and obscuring foliage, the 29 villas of 2,040-acre El Tamarindo epitomize the discreet retreat. They echo the resort's dining pavilion and adjacent pool on a personal scale. Guests can bike trails that extend across a golf course woven into the jungle, explore the shore in kayaks or have a massage in a breezy beach hut. Then follow spa director Reto Kade into the beachfront temazcal, a sweat lodge heated with rocks pulled from a bonfire.Pheasantlike birds known as chachalacas mark morning and evening with a riotous racket. Big white butterflies float by like flying handkerchiefs. And sea turtles come ashore, as they have for ages, to lay their eggs. As at the two other resorts, El Tamarindo protects the eggs from animal and human predators. Assisting the hatchlings to the water's edge, guests become part of an ancient cycle. Watching the tiny turtles wobble into the surf, knowing that only a few will make it back to reproduce, makes palpable the pulse of nature.And the desire to return. "When you come to this coast, you always come back," Giorgio declares. "Like a turtle -- only the odds are much better!" Fortunately, much of Costa Alegre will remain undisturbed for years to come, allowing repeat and first-time visitors to enjoy its not-so-secret splendors.