Disney's Animal Kingdom Theme Park is the fourth of four theme parks built at the Walt Disney World Resort in Bay Lake, Florida, southwest of Orlando. It was dedicated and opened to the public on Earth Day, April 22, 1998. It is the second largest theme park in the world, behind Six Flags Great Adventure in Jackson, New Jersey, and it is the largest Disney theme park in the world, covering 500 acres (200 ha), It holds the distinction of being the first (and only) Disney park to be themed entirely around animal conservation, a philosophy once pioneered by Walt Disney himself. Disney's Animal Kingdom is accredited by the Association of Zoos and Aquariums and the World Association of Zoos and Aquariums, meaning they have met or exceeded the standards in education, conservation, and research.