Almost 70 miles west of Key West lies the remote Dry Tortugas National Park. The 100-square mile park is mostly open water with seven small islands. The park is known the world over as the home of magnificent Fort Jefferson, picturesque blue waters, superlative coral reefs and marine life, and the vast assortment of bird life that frequent the area. Things To Do - Dry Tortugas National Park (U.S. National Park Service)