Seventy miles west of Key West, reachable only by seaplane or boat: a colossal Civil War sea fortress — 16 million bricks — rising from a sand island in water so clear the boats above it look airborne. Snorkel the moat wall over coral and tropical fish, wander Fort Jefferson's endless brick arches, and picture Dr. Samuel Mudd (Lincoln conspirator) imprisoned in the casemates you're standing in. Day trips sell out weeks ahead; camping under the fort's walls, with the day crowd gone and the Milky Way overhead, is one of Florida's ultimate nights. This is the most remote national park east of the Rockies, and it feels like it. Our charter option is linked. Click See deals