The Phoenix zoo houses over 1,300 animals on display and contains 2.5 miles of walking trails. It is divided into 4 main themed areas or trails: The Arizona Trail (American Southwest flora and fauna), the Africa Trail (animals from Africa), the Tropics Trail (residents of the rain forests), and the Children's Trail, which includes a petting zoo. The zoo has been conservation minded from its inception. Soon after it opened it hosted what was thought to be the last few Arabian Oryx, which formed the basis of the world herd created for Operation Oryx and eventually allowed the reintroduction of the species into the wild. It now includes a sanctuary to care for animals that are endangered or unwanted