Biscayne National Park
Ninety-five percent of this colorful park on Miami’s doorstep is underwater. Save for 30 islets and a mangrove forest fringe on the mainland, Biscayne is 173,000 acres of Caribbean-clear waters that wash over the sea-grass shallows of Biscayne Bay—and the world’s third largest coral reef.
Cool Fact: There are 72 shipwrecks in the park. Six are part of a Maritime Heritage Trail opening in late 2010. The 112-foot schooner Mandalay (a posh windjammer cruiser sunk in 1966) is shallow enough for snorkelers.
Don’t Miss: Some of the best snorkeling and scuba diving in the United States. Swim with manatees and more than 200 species of fish—colorful coral-nibblers, toothy silver barracuda, and 500-pound groupers.