Flamenco Beach, Culebra

Two rusting M4 Sherman tank hulks sit at Flamenco Beach like monuments to a former occupant who didn't clean up after himself. The U.S. Navy used Culebra as a weapons-testing ground for more than 30 years before leaving in 1975 — and the tanks were too heavy to bother moving. Locals and visitors have covered them in graffiti ever since. The mile-long, horseshoe-shaped beach itself is bordered by the Culebra National Wildlife Refuge and ranked third in the world by TripAdvisor in 2013. The Navy's gone. The beach won.