Dry Tortugas National Park is a national park in the USA about 68 statute miles (109 km) west of Key West in the Gulf of Mexico. The park preserves Fort Jefferson and the Dry Tortugas islands in the Florida Keys.
The park is famous for abundant sea life, colorful coral reefs and legends of shipwrecks and sunken treasures. The park's centerpiece is Fort Jefferson, a massive but unfinished coastal fortress. Fort Jefferson is the largest masonry structure in the Western Hemisphere, and is composed of over 16 million bricks. The park has almost 80,000 visitors each year. The park is accessible only by seaplane or boat. Ferries leave from Key West. Activities include snorkeling, picnicking, camping, scuba diving, saltwater fishing and birdwatching.