<Tr> <Th_colspan="2"> Geography </Th> </Tr> <Tr> <Th> Coordinates </Th> <Td> 2 ° 59 ′ 37" S 35 ° 21 ′ 04" E ﻿ / ﻿ 2.993613 ° S 35.35115 ° E ﻿ / - 2.993613; 35.35115 Coordinates: 2 ° 59 ′ 37" S 35 ° 21 ′ 04" E ﻿ / ﻿ 2.993613 ° S 35.35115 ° E ﻿ / - 2.993613; 35.35115 </Td> </Tr> <P> The Olduvai Gorge or Oldupai Gorge in Tanzania is one of the most important paleoanthropological sites in the world; it has proven invaluable in furthering our understanding of early human evolution . A steep - sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km (30 mi) long, and is located in the eastern Serengeti Plains in the Arusha Region not far, about 45 kilometres (28 miles), from Laetoli, another important archaeological site of early human occupation . The British / Kenyan paleoanthropologist - archeologist team Mary and Louis Leakey established and developed the excavation and research programs at Olduvai Gorge which achieved great advances of human knowledge and world - renowned status . </P> <P> Homo habilis, probably the first early human species, occupied Olduvai Gorge approximately 1.9 million years ago (mya); then came a contemporary australopithecine, Paranthropus boisei, 1.8 mya, then Homo erectus, 1.2 mya . Our species Homo sapiens, which is estimated to have emerged roughly 300,000 years ago, is dated to have occupied the site 17,000 years ago . </P>

Where is olduvai gorge located (what countries)