National Park Service, Florida.
Almost 70 miles (113 km) west of Key West lies the remote Dry Tortugas National Park. This 100-square mile park is mostly open water with seven small islands. Accessible only by boat or seaplane, 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 frequents the area.
Dry Tortugas National Park is one of the most remote parks in the National Park System. Located approximately 70 miles west of Key West it is accessible only by a daily concession ferry, private boats, charter boats, or seaplane.