The Ark of Noah in Africa: Ngorongoro Crater.

The main feature of the NCA is the Ngorongoro Crater, which is the world's largest unbroken, unflooded volcanic caldera. The Crater, which formed when a giant volcano exploded and collapsed on itself some two to three million years ago, is 610 m (2,001 ft) deep and its floor covers 260 km² (102 square miles). Estimates of the height of the original volcano range from fifteen to nineteen thousand feet (4500 to 5800 metres) high.

It also considered the Ark of Noah East Africa, for shelter within it for nearly all species of animals that region, in an integrated ecosystem that has not been affected by the hand of man. Observed the high cliffs of their or the bottom of its wide crater, the Ngorongoro is one of the most fascinating places in Africa.

The area is part of the Serengeti ecosystem, and to the north-west, it adjoins the Serengeti National Park and is contiguous with the southern Serengeti plains, these plains also extend to the north into unprotected Loliondo division and are kept open to wildlife through trans-human pastoralism practiced by Maasai. The south and west of the area are volcanic highlands, including the famous Ngorongoro Crater and the lesser known Empakai. The southern and eastern boundaries are approximately defined by the rim of the Great Rift Valley wall, which also prevents animal migration in these directions.

A population of approximately 25,000 large animals, largely ungulates along with reputedly the highest density of mammalian predators in Africa, lives in the crater. These include the black rhinoceros, whose local population declined from about 108 in 1964-66 to between 11-14 in 1995, and the hippopotamus, which is very uncommon in the area. There also are many other ungulates: the wildebeest (7,000 estimated in 1994), the zebra (4,000), the eland, and Grant's and Thomson's gazelles (3,000).

Aside from herds of zebra, gazelle, and wildebeest, the crater is home to the "big five" of rhinoceros, lion, leopard, elephant, and buffalo. The crater plays host to almost every individual species of wildlife in East Africa, with an estimated 25,000 animals within the crater.

In summer, enormous numbers of Serengeti migrants pass through the plains of the reserve, including 1.7 million wildebeest, 260,000 zebra, and 470,000 gazelles. Waterbuck occur mainly near Lerai Forest; servals occur widely in the crater and on the plains to the west.

The conservation area also protects Olduvai Gorge, situated in the plains area. It is considered the seat of humanity after the discovery of the earliest known specimens of the human genus, Homo habilis as well as early homonids, Paranthropus boisei.