4.9 / 5
Moderate
Full Day
Fall & Winter
Amenities & Activities
Fun Facts
Accessible only by boat or seaplane — making it one of the most remote national parks in the continental US.
Fort Jefferson, the park's centerpiece, is the largest 19th-century brick fortification in North America — it was never completed.
Hosts over 100,000 Sooty Terns in the largest nesting colony of this species in the United States.
99% of the park is open water and coral reef — only 1% is land.
Dr. Samuel Mudd, who set John Wilkes Booth's broken leg, was imprisoned here after Lincoln's assassination.
Seasonal Events
Sooty Tern Nesting Season
Over 80,000 Sooty Terns nest on Bush Key, viewable from Garden Key. Bush Key is closed to visitors during nesting.
Spring Bird Migration
Hundreds of migratory songbird species rest on the islands during spring migration — a bucket-list event for birders.
Sea Turtle Nesting
Loggerhead sea turtles nest on the beaches at night. Rangers conduct evening turtle watches.
Wildlife
Critical nesting habitat for the Sooty Tern (over 80,000 nesting pairs) and Brown Noddy. Loggerhead sea turtles nest on beaches May–September. Reef fish, nurse sharks, sea turtles, and rays are common in the crystal-clear waters around the fort. Spring migration brings hundreds of songbird species.
Visitor Tips
Book the Yankee Freedom III ferry weeks or months in advance — it sells out quickly in winter. Bring all food, water, and supplies; nothing is sold on the island. Snorkeling around the fort moat wall is spectacular and suitable for all skill levels. Campers get the island to themselves after the day-trippers leave.
Safety Notes
No freshwater on the island — all visitors must bring their own water. No shade outside the fort; sunscreen and hats are essential. Rough seas may cancel ferry service. Snorkelers should watch for boat traffic and currents around the moat wall.