The jewel in Ngorongoro's crown is a deep, volcanic crater, the largest unflooded and unbroken caldera in the world. About 20kms across, 600 metres deep and 300 sq kms in area, the Ngorongoro Crater is a breathtaking natural wonder. The rich pasture supports over 25,000 animals, predominantly grazing animals, including some of Tanzania's last black rhinos. Big tuskers roam the floor and even though animals are free to leave or enter the Crater, most remain because of the plentiful water and food available on the Crater floor throughout the year.

Steep inner slopes give way to open grasslands which cover most of the floor with several species of grasses that are the main food source for most of the larger grazing animals.
Lake Makat, fed by the Munge River is a soda lake and a magnet for flamingos and other water birds which come here to feed.
The crater is a dynamic and changing ecosystem and the numbers and proportion of some animals has fluctuated over the last thirty years.