St. Lucia, a teardrop-shaped island in the Lesser Antilles, nestled between St. Vincent and Martinique, is the tropical paradise you see on postcards come to life. And Jade Mountain, a 600-acre resort perched on its jagged southwestern shore, is the sultry spot where anyone would gladly be marooned. The lush retreat is nirvana for adventurers and hedonists alike, from its extravagant beachside spa to its famous dive spots, extensive mountain-biking trails, and stunning natural

St. Lucia, a teardrop-shaped island in the Lesser Antilles, nestled between St. Vincent and Martinique, is the tropical paradise you see on postcards come to life. And Jade Mountain, a 600-acre resort perched on its jagged southwestern shore, is the sultry spot where anyone would gladly be marooned. The lush retreat is nirvana for adventurers and hedonists alike, from its extravagant beachside spa to its famous dive spots, extensive mountain-biking trails, and stunning natural architecture.

Picture a three-walled suite (the fourth side is completely open to the wide, sapphire-hued Caribbean) with a 15-foot-high ceiling and a private "infinity pool" that seems to spill from the room and out into the lapping sea. Plus entry doors made of huge, rough-hewn slabs of tropical hardwood and a space outfitted with locally-made furniture and luminescent tubs handcrafted with recycled glass tiles. These organic architectural features are just part of the jaw-dropping appeal of Jade Mountain, the ultra-exclusive extension of the Anse Chastanet resort (long known as one of the Caribbean's premier lodges).

The refuge of Jade Mountain sits high on the Morne Chastanet, just above the main resort. The secluded estate is infused with the scent of hibiscus and a total air of luxury. Banana, breadfruit, papaya, and mango trees envelop the area. Beneath Jade Mountain lie two powder-soft, palm-lined beaches and, just 30 feet offshore, the Anse Chastanet Reef, which beckons snorkelers and divers to view its Technicolor undersea spectacle.

Jade Mountain's 24 suites, or "sanctuaries" as they're known in-house, are techno-free (no telephones, radio, or television). They're boldly designed with wide sweeping spaces where one room flows into the next, and all of it extends outdoors to meet the warm tradewinds. The dramatic feel of the resort's not-entirely-interior spaces harmonize with the extraordinary topography of the island, including St. Lucia's two remarkable, rocky pitons (part of a UNESCO World Heritage site) that can be seen from every suite. These iconic triangular monoliths pierce the surface of the Caribbean and soar nearly 3,000 feet into the air.

The Pitons, like the rest of this tropical playground, are there for the exploring. Guided hikes of 2,619-foot Gros Piton can be arranged through the resort. Or guests can steer one of the resort's high-end mountain bikes through the remains of a 19th-century French plantation on 12 miles of private trails. Before long, the azure water coaxes snorkelers, windsurfers, sea kayakers, Sunfish sailors, and scuba divers into action. Jade Mountain has a Platinum/PADI scuba center on-site and organizes dives for all abilities. The Anse Chastanet Reef boasts over 150 different fish species in 20 to 140 feet of crystalline water. Snorkelers might see turtles, needlefish, peacock flounder, and even octopus among the multi-colored coral; dive deeper and you may be swimming with parrotfish, moray eels, and puffers.

A day at Jade Mountain might end by swaying gently in a beach hammock, getting a "Wosh Cho" hot-stone massage at the Kai Belté Spa, or enjoying a cool drink (complete with tiny paper umbrella) in the comfortable bar while being soothed by the sounds of local musicians and a breeze through the coconut palms.

Heather Hansen is co-author of and has written for publications including Men's Journal, Outside, and Mother Jones.