Ngorongoro Crater, an extinct volcano with a caldera about twenty kilometers in diameter and a depth of 610 m, is located in the eastern branch of the Great Rift. At an altitude of over 2, 400 m, it is the largest intact caldera in the world. The walls are covered with a forest accumulating the water, it will return to the dry season. So many animals find food to eat throughout the year. The crater floor is almost flat with a permanent lake, Lake Makat, which collects rainwater and the water of a small river.