The Dry Tortugas are a small group of islands, located in the Gulf of Mexico at the end of the Florida Keys, United States, about 67 miles (108 km) west of Key West, and 37 miles (60 km) west of the Marquesas Keys, the closest islands. Still further west is the Tortugas Bank, which is completely submerged. The first Europeans to discover the islands were the Spanish in 1513, led by explorer Juan Ponce de León.