Mariners Beware!

The Dry Tortugas offer a sheltered harbor for ships, but their reefs and shoals have claimed more than 200 wrecks since the 1500s. To warn mariners, the U.S. government built a 70-foot lighthouse in 1825–26 on Garden Key, 20 years before work started on the fort. Shipwrecks continued because the light was not tall or bright enough and was too far away from the hazards. In 1858 a new 152-foot lighthouse, with a powerful Fresnel lens, was built three miles to the west on Loggerhead Key. Damaged by hurricanes, the Garden Key Light was replaced in 1876 by the iron-plate lighthouse currently atop the fort, with iron used because bricks could shatter if hit by enemy fire and send debris flying into the fort.