Florida’s second-largest national park after the Everglades, Biscayne National Park, covering 172,924 acres, lies mostly underwater. It’s not entirely about the Big Blue, however, with a knotty and intricate ecosystem of mangrove shoreline, shallow bays, and deserted cays giving way to the park’s bright and brimming coral reefs. Scuba-diving and snorkeling are the best ways to experience the park, with kayaking, fishing, birding, and even hiking making the list of other popular activities. For an interesting glimpse into Biscayne’s signature attraction put to above-water use, don’t miss the nearby (in Homestead) Coral Castle, a quirky roadside stop featuring more than 1,000 tons of coral rock sculpted by one man between 1923 and 1951.