Criterion (x): Everglades National Park is a noteworthy example of viable biological processes. IntegrityEverglades National Park, at 610,670 hectares, of which 567,000 hectares were inscribed as a World Heritage site (the park has since been expanded), is at the center of a complex of federal and state (Florida) protected areas, including the Big Cypress National Preserve (295,000 hectares), Biscayne National Park (70,000 hectares), Dry Tortugas National Park (24,300 hectares), 10 National Wildlife Refuges, and the Florida Keys National Marine Sanctuary. Within Everglades National Park strict natural, managed natural and developed zones have been identified, and 86% of the park is in federally legislated wilderness. Protection and management requirementsDesignated by the U.S. Congress in 1934 as a national park, Everglades National Park is managed under the authority of the Organic Act of August 25, 1916 which established the United States National Park Service (NPS). In addition, the NPS has established Management Policies which provide broader direction for all units nation-wide, including Everglades National Park.