A steep-sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km long, and is located in the eastern Serengeti Plains within the Ngorongoro Conservation Area in the Olbalbal ward located in Ngorongoro District of Arusha Region, about 45 kilometres (28 miles) from Laetoli, another important archaeological locality of early human occupation.

The British/Kenyan paleoanthropologist-archeologist team of Mary and Louis Leakey established excavation and research programs at Olduvai Gorge that achieved great advances in human knowledge.

[3] The locality is significant in showing the increasing developmental and social complexities in the earliest Hominina, largely revealed in the production and use of stone tools.

Prior to tools, evidence of scavenging and hunting can be noted—highlighted by the presence of gnaw marks that predate cut marks—and of the ratio of meat versus plant material in the early hominin diet.

After the war, as Tanganyika came under British control, Louis Leakey visited Reck in Berlin and viewed the Olduvai fossils.

Louis Leakey became convinced that Olduvai Gorge held stone tools, thinking the deposits were of similar age to the Kariandusi prehistoric site in Kenya.

In May 1960, at the FLK North-North site, the Leakeys' son Jonathan found the mandible that proved to be the type specimen for Homo habilis.

Manuports are abundant at the MNK (Mark Nicol Korongo) site in addition to a chert nodule quarry containing over 14,000 pieces, including gneiss and lava anvils and hammerstones.

Dunes formed after the deposition of Oldonyo Lengai tuffs make up the upper portion of the Ndutu Beds, but yield few fossils.

[3]: 70–72 The few Australopithecus boisei remains, which include the skull, a thigh bone fragment, and several teeth, were found distributed throughout Beds I and II, which dates them in the range 1.1 to 2 mya.

They also identified the Developed Oldowan as the subsequent diverse tool-kit found in Beds II, III, and IV, with small tools made mostly from chert rather than quartzite.

[3]: 88, 90, 95, 98 Besides the chert quarry in Bed II, the Leakeys were able to identify the other source locations of the principal rocks used to make the stone tools.

These attributes suggested the species engaged in heavy chewing, indicating a diet of tough plant material, including tubers, nuts, and seeds—and possibly large quantities of grasses and sedges.

Beginning 1.7 million years ago, early Homo erectus apparently inherited Oldowan technology and refined it into the Acheulean industry.

that hominins inhabiting the area between 1.9 and 1.7 million years ago spent the majority of their time gathering wild plant foods, such as berries, tubers and roots.

Speculation about the amount of meat in their diets is inferred from comparative studies with a close relative of early hominins: the modern chimpanzee.

Thus, it can be assumed that early hominins had similar diet proportions, (see the middle-range theory or bridging arguments—bridging arguments are used by archaeologists to explain past behaviors, and they include an underlying assumption of uniformitarianism.)

Much of the information about early hominins comes from tools and debris piles of lithic flakes from such sites as FLK-Zinjanthropus in Olduvai Gorge.

She states in her article "Life in Olduvai Gorge" that early hominins, "knew the right angle to hit the cobble, or core, in order to successfully produce sharp-edged flakes ...".

She noted that selected flakes then were used to cut meat from animal carcasses, and shaped cobbles (called choppers) were used to extract marrow and to chop tough plant material.

Since several kinds of marks are present together, some archaeologists including Lewis Binford think that hominins scavenged the meat or marrow left over from carnivore kills.

Joshua Mwankunda conceived the idea of erecting a monument to commemorate this significant site while also serving as a signpost and attracting visitors to the Olduvai Gorge and museum; paleoanthropologists Nicholas Toth, Kathy Schick, and Jackson Njau planned and provided life-size fossil casts at the request of the Tanzanian government, which were used by the celebrated Tanzanian artist Festo Kijo to create the two large concrete skulls.

The fossil skulls depicted are Paranthropus boisei and Homo habilis, two contemporary species which were first discovered at Olduvai Gorge.

The monument project was funded by the Stone Age Institute and the John Templeton Foundation, in partnership with the Ngorongoro Conservation Area Authority (NCAA).