Playa Paraiso is everything the name implies: a 2.5-mile-long stretch of white sand on a 17-mile-long uninhabited island 60 miles off Cuba’s southwest coast. Between swaying palms and 73-degree turquoise water, the only sign of civilization is a palapa bar that serves rum and cigars. Getting there is still illegal—you need to fly north to Canada, then south on one of four weekly direct flights to Cayo Largo from Montreal or Toronto. It’s worth it. Thanks to Cuba’s political isolation and protective geography, the coral reef off Cayo Largo is the largest and best preserved submerged shelf in the Caribbean. Stay in one of seven simple, clean wooden cottages on a beach near the marina (from $56; 12-dive packages, $480).