Biscayne National Park

Ninety-five percent of Biscayne National Park is water, which makes it the rare national park where the main thing to do is go under. The Florida Reef is the only living coral barrier reef in the continental U.S., and the Biscayne Maritime Heritage Trail strings together historic shipwrecks you reach by boat. If staying dry matters, a boat tour covers Stiltsville's strange stilted homes and the old lighthouse on uninhabited Boca Chita Key.