The Olduvai Gorge is about 48 kilometres long and up to 90 metres deep. It is a rich archaeological site, where evidence of the first humans has been found. The gorge is located in the Great Rift Valley, between the Ngorongoro Crater and the Serengeti National Park.
Tanzania 1965, Ulduvai Gorge.
Kenya 1988, Olduvai Gorge.
Tanzania 1991(1989), Olduvai Gorge.
The stamp was issued in the series "Historical Craters and Caves".
In the background (the two rocky hills) is shown the extinct Lemagrut volcano.
Gambia 1992, Olduvai Gorge.
Tanzania 1995, Olduvai Gorge.
Tanzania 2002, Olduvai Gorge.