Dry Tortugas National Park - Florida
This remote 100-square-mile park sits in the Gulf of Mexico 70 miles west of Key West, Florida. Nearly all the park is open water, though there are seven small islands. The most important is Garden Key, home of massive Fort Jefferson, built in the mid-1800s to protect strategic US anchorages and shipping lanes. The park protects this historic site as well as corral reefs, marine and other bird life, the surrounding sea, and sea turtles (las tortugas) for which the area was named. Primary park activities include historic tours, swimming, snorkeling, scuba diving, picnicking, fishing, and birding.