This is where millions of years ago our ancestors lived and, the remains found, tell us how their life was over 2 million years ago.
It’s an exciting experience to venture in this steep ravine where the history of mankind began.
There is also a small museum showing all the fossils and tools unearthed in the area, which help reconstruct mankind’s evolution.

Olduvai Gorge is located in the Great Rift Valley, South-East of the Serengeti National Park, in the vicinity of Lake Masek, and is accessible from the Ndutu or Naabi area; it forms part of the Serengeti Ecosystem and here, from December to April, you can view herds of wildebeests and zebras during the Great Migration.

From a landscape point of view is a gorge, like many others in the world, which was formed through weathering and the erosion of the waters of the rivers that flow and contribute to form Lake Masek; where there is also a monolith similar to the ones in the Monument Valley in the United States.

What makes Olduvai truly unique are the artifacts that have been discovered over the years, thanks to the wise work of archaeologists and paleoanthropologists.
In fact, hundreds of fossilized bones and stone tools belonging to our ancestors have been found in what is the most important archaeological site in Tanzania, and one of the most significant of the entire African continent.

Thanks to these findings, in addition to those of the Omo Valley in Ethiopia and Taung in South Africa, it can be stated that humans evolved in Africa and, therefore, Olduvai is often referred to as "the cradle of mankind" and, because of the value it represents for our history, it was declared a World Heritage by UNESCO in 1979.

Olduvai is a misspelling of Oldupai, a Masai word for a wild sisal plant that grows in the area.

The steep Olduvai Gorge is about 48.2 km long and 89.9m deep, not large enough to be classified as a canyon, but it is defined as a “ravine”, i.e. a narrow gorge flanked by rocky walls gauged out by a river.

The site was discovered accidentally in 1911 by German entomologist, Wilhelm Kattwinkel, who was chasing a butterfly to capture it for study reasons; he casually fell into the gorge and when he recovered he realised the importance of that layered fault.
 
It is believed that millions of years ago in this area there was a lake whose beaches were covered with volcanic ash; about 500,000 years ago, after intensive seismic activity, the course of a river was diverted to where it is today.
 
Over the millennia, the river eroded the valley and opened the way between sediments, bringing to light seven different sedimentary layers in the walls of the gorge.

Fossil remains of 60 hominids or so were unearthed; they cover a time period ranging from the appearance on earth of Australopithecus to Homo Sapiens, i.e. the species to which we belong.

 
From the fossil beds of Olduvai it is possible to reconstruct the events of mankind’s evolution; as many as seven major stratification units, from the oldest to the youngest have been classified, namely:
 
Bed I,   dated 1.75 to 2.5 million years ago
Bed II, dated 1.2 to 1.75 million years ago
Bed III, dated 800,000 to 1.2 million years ago
Bed IV, dated 600,000 to 800,000 years ago
Masek Bed, dated 400,000 to 600,000 years ago
Ndutu Bed, dated 32,000 to 400,000 years ago
Naisiusiu Bed, dated 15,000 to 32,000 years ago
 
Bed I, the oldest deposit, is as much as 60 m thick and mainly consists of lavas overlain, volcanic deposits and sedimentary deposits. 
It mainly contains traces of encampments and tools made of basalt or quartz, which were used to produce sparks; these tools are called “Olduvian” just because they were found at Olduvai.
 
It is thought that the first hominids began creating these tools about 2.5 million years ago.
 
It was in Bed I that in 1959 the English archaeologist Mary Leakey discovered a fragment of a skull belonging to a hominid, who Mary’s husband Louis Leakey originally called Zinjanthropus boisei, later reclassified as Australopithecus boisei.
 
This finding was officially labelled OH 5, the acronym for Olduvai Hominid 5; this Australopithecus was also nicknamed “Nutcracker man” because of his huge molars, which is indicative of a predominantly vegetarian diet.
 
Bed I also revealed remains of a Homo habilis dating back to about 1.75 m.y.a., who is believed to be the creator of the tools found there.
 
More elaborated and sophisticated tools attributable to the Home Ergaster and dating back to 1.75 and 1.2 m.y.a. have been found in Bed II, which lies immediately above Bed I.
 
In Beds III and IV fossil tools and bones of the Acheulian period, dating back to more than 600,000 years ago, have been found.
 
More elaborated objects belonging to the Homo Sapiens have been found in younger layers.
 
On the edge of the gorge, 5 km away from the road leading to the Serengeti National Park,  there is the Olduvai Gorge Museum, which was founded by Mary Leakey to collect the exhibits and artifacts found in the Gorge and at Laetoli, an area located about 50 km away from the Olduvai Gorge.
One of the rooms is devoted precisely to the Leakeys, with photographs of the excavation work and maps and documents reporting the process of excavation of fossils.
 
Many of the items exhibited in the museum are original findings, other are casts, namely those of hominid skulls.
 
A whole room is devoted to Laetoli fossil footprints and papers explaining the process of formation of these footprints, as well as maps and photographs of the finds.