Flamenco Beach, Culebra

Two rusting M4 Sherman tanks sit at Flamenco Beach as unlikely monuments — left behind when the U.S. Navy departed Culebra in 1975 after more than 30 years of using the island as a weapons-testing ground. Locals and visitors have covered the corroding hulks in layers of graffiti ever since. The horseshoe-shaped beach itself stretches about a mile around a reef-sheltered bay, with shallow turquoise water and white sand, and has ranked among the top beaches in the world by TripAdvisor multiple years running. It is bordered by the Culebra National Wildlife Refuge.