Back in 2001, the Navy was still using Puerto Rico's Vieques for war games on the beaches. There was just a handful of restaurants and hotels on the 21-mile-long, four-mile-wide Caribbean island, and it was the kind of place where guests didn't wear shoes. Today, the Navy is gone and the old bombing ranges have been designated a national wildlife refuge. Now, Vieques is exploding in a different way: New roads are being built; old ones are getting paved. One of the military's old bunkers is now a sports bar by day and a disco by night. Swanky hotels, like the W, which opened in March (doubles from $379; wvieques.com), and restaurants, like El Quenepo (787-741-1215), are popping up.
But don't worry. While it's now possible to have the resort experience, Vieques is still funkier and more laid-back than most Caribbean islands. Book a cabañita—one-room cottage—at La Finca (doubles from $125; lafinca.com), a clean but rustic joint with outdoor showers and mismatched towels. Then head for the sand. There are more than 50 beaches—perfect for everything from kayaking (Green Beach) to snorkeling (the islet of Blue Beach) to paddling at night in one of the biggest bioluminescent bays in the world (Puerto Mosquito, a.k.a. "Bio Bay"). The best way to see the latter is in a clear canoe from the Vieques Adventure Company (two-hour rentals, $45; viequesadventures.com), which, should you start getting antsy for more action, can also set you up with decent mountain bikes to explore all the old military roads ($25 per day) or take you kayak fly-fishing for tarpon ($150).