Dry Tortugas: The Island Fortress 70 Miles Past the End of the Road

Seventy miles west of Key West, past the last sliver of land most people will ever see, a six-sided brick fortress rises out of the Gulf of Mexico like something that got lost on the way to a different century. Fort Jefferson covers 16 acres of Garden Key in the Dry Tortugas, built from over 16 million bricks, and it was never finished. It is the largest brick masonry structure in the Americas, and it sits in a national park that is 99 percent underwater.

A Fort That Never Fired a Shot

Construction began in 1846 to protect one of the deepest natural harbors in North America. The U.S. military wanted a stronghold to control shipping lanes through the Gulf of Mexico and the Straits of Florida, and Garden Key was the spot. Workers (many of them enslaved people hired from owners in Key West) spent over 30 years stacking bricks in brutal heat, battling mosquitoes, hurricanes, and yellow fever. The fort was designed to hold 450 guns and a garrison of 1,500 soldiers. It never saw combat. By the time the Civil War broke out, advances in rifled cannon had already made its thick brick walls obsolete.

America’s Devil’s Island

What Fort Jefferson lacked as a military post, it made up for as a prison. During and after the Civil War, the fortress held over 2,500 prisoners in conditions so harsh it earned the nickname “America’s Devil’s Island.” The most famous inmate was Dr. Samuel Mudd, convicted of conspiracy in the assassination of Abraham Lincoln for setting John Wilkes Booth’s broken leg. Mudd served four years before earning a pardon, partly for treating soldiers and prisoners during a devastating yellow fever outbreak on the island.

Getting There Is Half the Story

The Dry Tortugas are reachable only by boat or seaplane from Key West. The Yankee Freedom III ferry makes the 2.5-hour trip daily, and Key West Seaplane Adventures offers 40-minute flights with a view that makes the fare worth every penny. The park allows camping on Garden Key (bring everything, including water), and the snorkeling around the fort’s moat wall is some of the best in the Florida Keys. Bush Key, just a short walk across a sand spit, hosts up to 80,000 nesting sooty terns each spring. Over 200 shipwrecks lie within the park’s boundaries, some dating to the 1600s. The park is open year-round, and entry is $15 per person.

Official page: Dry Tortugas National Park