Flanking the eastern edge of the Serengeti, the site houses the Ngorongoro Crater – the world's sixth-largest intact volcanic caldera – and Olduvai Gorge. This UNESCO World Heritage site ...
The Olduvai Gorge in northern Tanzania has a geology that fossil-hunters love. A river cuts through several layers of strata with four distinct beds. Bed I, the oldest, is about 2 million years old.