2 Best Sights in Vieques and Culebra, Puerto Rico

Commissioned by President Theodore Roosevelt in 1909, the Culebra National Wildlife Refuge is one of the nation's oldest. The total protected area comprises some 1,500 acres of the island. It's a lure for hikers and bird-watchers: Culebra teems with seabirds, from laughing gulls and roseate terns to red-billed tropic birds and sooty terns. Maps of trails in the refuge are hard to come by, but you can stop by the U.S. Fish and Wildlife Service office east of the airport to find out about trail conditions and determine whether you're headed to an area that requires a permit. The office also can tell you whether the leatherback turtles are nesting. From mid-April to mid-July, volunteers help monitor and tag these creatures, which nest on nearby beaches, especially Playa Resaca and Playa Brava.

A portion of the west and the entire eastern end of the island is administered by the U.S. Fish and Wildlife Service as the Vieques National Wildlife Refuge. With almost 18,000 acres, it's Puerto Rico's biggest protected natural reserve; in 2015, it was voted the fourth-best refuge in the entire Fish and Wildlife system. Many of the beaches on the northern and southern coasts—where an asphalt road leads to six of them—are open to the public. Hiking, biking, and horseback riding are allowed on designated trails. Fishing (both shore and from kayak), swimming, snorkeling, and diving are also permitted in designated zones. Much, though not all, of the eastern region is pristine, astonishingly beautiful, and well forested, with a hilly center region overlooking powder-white sandy beaches and a coral-ringed coastline. Some of the refuge—including 900 acres that once served as a naval bombing range—remains off-limits to visitors, though, as authorities continue to search for unexploded munitions and contaminants, the byproducts of the area's 60 years as a military base.