Ngorongoro Crater, Tanzania
Ngorongoro Crater is the main feature of the Ngorongoro Conservation Area, located 180 km west of Arusha in the Crater Highlands area of Tanzania. It is the world's largest inactive, intact, and unfilled volcanic caldera. The crater, which formed when a large volcano exploded and collapsed on itself two to three million years ago, is 610 m deep and its floor covers 260 sq km. Estimates of the height of the original volcano range from 4,500 to 5,800 m. The elevation of the crater floor is 1,800 m above sea level. Approximately 25,000 large animals live in the crater, including the black rhinoceros, the African buffalo, and the hippopotamus. There also are many other ungulates: the blue wildebeest, Grant's zebra, the common eland, and Grant's and Thomson's gazelles. Waterbucks occur mainly near Lerai Forest.