Everglades National Park features one of the most diverse ecosystems in the USA. The park protects an unparalleled landscape of swamps, marshes, tall grass prairies and mangroves. It is home to rare and endangered species including the Florida panther, the American crocodile, and the West Indian manatee. Though the scenery is beautiful, Everglades National Park was actually the very first park designated primarily to preserve the biodiversity contained within it rather than just the views. It has been declared a World Heritage Site, an International Biosphere Reserve, and a Wetland of International Importance. The Everglades are a haven for birds, reptiles, fresh and saltwater fish and mammals. The Everglades National Park is the largest subtropical wetland in North America and it is known as the "River of Grass" for its slow moving water.