Biscayne National Park is one of the few Park System units primarily designated to protect an underwater environment, and it was one of the first units so designated. Originally a National Monument, it was "promoted" to National Park status in 1980. The park consists of much of Biscayne Bay, plus several barrier islands, which form the northeastern end of the Florida Keys.

Originally created in response to development plans which would have destroyed the local habitats with hotels, roads, an airport, and businesses, the park now provides a quiet oasis just south of the metropolis of Miami. Concessionaires offer boat trips into the park, including snorkeling trips, though visitors can use their own boat to access the campgrounds and trails on the uninhabited islands dotting the park.

A small section of the park extends onto the mainland where a Visitor Center is located, along with a short trail along the shoreline and extending on a jetty into the bay itself.