Fort Jefferson If you drive to the very end of US-1 in Key West, you will hit a marker that says "90 Miles to Cuba." Most tourists take a picture, buy a margarita, and think they have reached the end of Florida. They haven't. If you get on a boat and head 70 miles further west into the open ocean, you will find something that looks like it belongs in a fantasy novel: a massive, hexagonal brick fortress rising straight out of the turquoise water. This is Dry Tortugas National

Beneath the flat surface of the Sunshine State lies a massive honeycomb of limestone. While most of these Swiss-cheese holes are filled with water (our aquifer), a few rare spots have risen above the water table to create spectacular, air-filled cathedrals of stone. You don't need to go to Tennessee or Virginia to see stalactites. You just need to know where to look.