The ravine on the road to the Serengeti
Olduvai Gorge cuts across the plains in the western part of the Ngorongoro Conservation Area, close to the road running between the crater and the Serengeti. That position is why it is one of the few genuinely famous archaeological sites in the world that most visitors reach as a stop on a transfer day rather than as a destination.
The Ngorongoro Conservation Area Authority uses the spelling Olduvai throughout its own material, while Oldupai, closer to the Maasai word for the wild sisal that grows in the gorge, appears in other official Tanzanian usage. Both refer to the same place.
What the authorities publish, and where they differ
The NCAA gives the gorge a length of 55 kilometres and a depth of 100 metres. UNESCO, in the World Heritage documentation for the property, describes it instead as a 14-kilometre deep ravine. Those are not reconcilable and neither body explains the difference, so both stand. The NCAA figure is the one most often quoted onward.
The site was included when Ngorongoro was inscribed as a World Heritage property in 1979, and the gorge is the principal reason the property carries a cultural criterion at all rather than being a wildlife site alone.
What was found here
The NCAA describes the exposed sides of the gorge as holding a chronicle of human ancestry and of the evolution of the Serengeti ecosystem. Excavation has continued since the 1930s. Mary and Louis Leakey worked here across more than thirty years, and the finds the authority names are the Zinjanthropus skull, now generally called Australopithecus boisei; remains of Homo habilis, the presumed maker of the early stone tools recovered from deposits the NCAA dates between 1.6 and 1.8 million years old; and Homo erectus.
The gorge may be visited year-round. An official guide is required to visit the actual excavations, which is the NCAA’s own wording and the one practical rule that catches people out.
What a visit actually involves
For most travellers a visit means the museum on the gorge rim, the viewing platform, a talk from a curator, and a guided walk down to the Zinj site where the Zinjanthropus cranium was found — a kilometre from the museum by the NCAA’s reckoning. The Olduvai museum has its own page here.
What it does not involve is an active dig with people in it. Fieldwork runs through the dry seasons under the NCAA’s Cultural Heritage Department; some sites have been prepared for public viewing and the rest have not. The gorge itself reads, from the rim, as a dry eroded ravine in an enormous flat landscape. The interest is entirely in what the layers mean, which is why the curator’s talk is the part that makes or breaks the stop.
Two other sites sit close by and are often confused with this one. Laetoli, where the 3.6-million-year-old hominin trackway was found, is a separate site on the southern edge of the Serengeti plains and is not open to visitors; the museum holds replicas. The Shifting Sands dune lies about ten kilometres from the museum. See archaeological tours.
Common questions
How long is Olduvai Gorge?
The NCAA gives 55 kilometres long and 100 metres deep. UNESCO describes a 14-kilometre deep ravine. The two figures come from different authorities and neither explains the other.
Do you need a guide?
To visit the excavation sites themselves, yes — the NCAA requires an official guide. The museum and the rim viewing area are ordinary visitor facilities.
Is Olduvai the same as Oldupai?
Yes. Oldupai is closer to the Maasai word for the wild sisal that grows in the gorge. The NCAA uses Olduvai in its own material.
How long does a stop take?
An hour covers the museum and the viewing platform. Adding the guided walk down to the Zinj site, a kilometre away, makes it half a morning. It fits comfortably into the drive between Ngorongoro and the Serengeti.