The Dry Tortugas are a group of islands in the Keys about 70 miles west of Key West. With the surrounding waters, they make up Dry Tortugas National Park. The word "dry" was used in the name because there is no naturally occurring fresh water here. The area is known for its abundant sea life, coral reefs, shipwreck sites and sunken treasures. About 80,000 visitors come there yearly to snorkel, scuba dive, fish and birdwatch. Birdwatching peaks in spring when dozens of migratory bird species can pass through the park in a single day.
Pictured here is Fort Jefferson, an unfinished fortress located in the Dry Tortugas (on Garden Key) that once served as a prison. It is the largest masonry structure in the western hemisphere, consisting of over 16 million bricks.