Dry Tortugas National Park

Location: Florida

Year Established: 1992

Area: 64,701.22 acres (261.8 km2)

Annual Visitors: 64,865

The islands of the Dry Tortugas, at the westernmost end of the Florida Keys, are the site of Fort Jefferson, a Civil War-era fort that is the largest masonry structure in the Western Hemisphere. With most of the park being remote ocean, it is home to undisturbed coral reefs and shipwrecks and is only accessible by plane or boat.