One of the most unique activities that can be done from Key West is touring the Dry Tortugas National Park by boat or floatplane. Located about 70 miles west of Key West, these islands are brimming with natural beauty and history. First discovered by Ponce De Lion and named for the turtles he found there, the word dry was later added because of the lack of fresh water available on the islands. The main landing on the islands is on Garden Key, which hosts Fort Jefferson. The fort was never completed after thirty years of construction, but still was used as a union outpost during the civil war, and then as a prison where Dr. Samuel Mudd was imprisoned for treating John Wilkes Booth. These small uninhabited keys are one of the most amazing landscapes in the continental united states, demonstrating what the keys looked like before human habitation.