Fort Jefferson Dock

Garden Key in the Dry Tortugas is the site of the historic Fort Jefferson. Fort Jefferson is a massive but unfinished coastal fortress. It is the largest masonry structure in the Americas and is composed of over 16 million bricks. It nearly encompasses the entirety of Garden Key. Garden Key is one of the seven keys in the Dry Tortugas National Park. Although manned for several years, changes in naval warfare outmoded the fort before it could be completed.