You can’t actually set foot on this uninhabited 1.5 square kilometer island refuge, which was once used by the U.S. military for bombing practice, but its surrounding waters contain some of the best diving spots in the Caribbean. Scuba enthusiasts and snorkelers can book tours and explore the underwater walls, caves and reefs which are full of vibrant sea life, including starfish, eels, turtles and hundreds of varieties of colorful tropical fish. Numerous outfitters in Rincon offer half-day excursions to the island. In 1976 administration of the island was given to the U.S. Fish and Wildlife Service and in 1983 it was designated as a National Wildlife Refuge.