Biscayne National Park is located in Florida, south of Miami. The park preserves Biscayne Bay and its offshore barrier reefs, some of the top scuba diving & snorkeling areas in the United States. 95 percent of the park is water, and the shore of the bay is the location of an extensive mangrove forest. The park includes Elliott Key, the park's largest island and first of the Florida Keys, formed from fossilized coral reef. The islands farther north in the park are transitional islands of coral and sand. The offshore portion of the park includes the Florida Reef, one of the largest coral reefs in the world.
The bay waters harbor immature and adult fish, seagrass beds, sponges and soft corals, as well as manatees. Offshore reefs and waters harbor over 200 species of fish, pelagic birds, whales and hard corals. Sixteen endangered species including the Schaus' swallowtail butterfly, smalltooth sawfish, manatees, and green and hawksbill sea turtles may be observed in the park.