The park and the Key Largo National Marine Sanctuary are 20 miles long and contain about 103 square nautical miles altogether and is the first undersea park in the United States. Check out this site for more info. The only ecosystem of its kind in the world, encompasses some 1.4 million acres. Visitors see bald eagles and many of the 300 other species of birds found in the park as well as alligators, deer and bobcats. Activities include guided tours, canoeing, fishing, camping and hiking.
Accommodations are available at the park and nearby.
The park offers a playground, swimming areas, a softball field, picnic tables, grills and a boat ramp. In Time Spanish Treasure is a veritable gold mine of information and actual authentic artifacts collected from the most famous shipwrecks in history. The museum showcases shipwreck remnants from 10 different sites, including the world-famous Atocha. The boat is on display, free of charge at MM 100 Marina. Rides can be arranged.