Dry Tortugas & Fort Jefferson
The name "Dry Tortugas" comes from the island itself. When Ponce de Leon discovered the island, he was amazed by the amount of sea turtles, "Tortugas" means turtles in Spanish, in the waters surrounding the island. Later, "Dry" was added to the name of the island to inform sailors that they would need to bring their own fresh water to drink.
The Dry Tortugas currently possess one of the richest concentrations of shipwrecks in North America. Because of the large reefs surrounding the Tortugas, the U.S. established one of the most strategic harbors in it's history: Fort Jefferson.
Following the War of 1812, a number of forts were build all along the eastern sea-coast of the US, as well as along the shores of the Gulf of Mexico. Fort Jefferson was just one of them. It was build in a six-sided / hexagonal shape, so as to have a full 360 degree view of the island and surrounding waters. And was one of the largest brick built buildings in the US, numbering over 16 million, hand made, individual bricks.
Today, the Dry Tortugas/Fort Jefferson is a national park offering some of the best snorkeling and SCUBA diving in North America. Visitors can take the Yankee Freedom III from the same terminal that the Key West Express leaves from, in order to experience the island.