Do you know the first undersea park in the United States? It’s John Pennekamp Coral Reef State Park in Key Largo, Florida, established in 1963. Home to the only living coral reef in the continental United States, snorkelers and divers will enjoy the colorful fish and sea creatures found in the clear turquoise waters of the Atlantic Ocean. If you prefer not to get wet, the park also has glass bottom boat tours as well as power boat and kayak rentals. Campsites are available but very popular so reservations are a must.