Biscayne National Park in southeast Florida protects a mostly marine landscape of Biscayne Bay, mangrove shoreline, coral-limestone keys, and the northern end of the Florida Reef. Defined far more by water than land, it includes seagrass meadows, reefs, islands, and four linked ecosystems that support rich marine life and threatened species such as sea turtles, smalltooth sawfish, and American crocodiles. Its islands and reefs also preserve deep geological history and a long human past, from early Indigenous occupation to shipwrecks, farming, private retreats, and Stiltsville. Growing development threats led to federal protection in 1968 and national park status in 1980.