On our way to Serengeti we passed Oldupai Gorge (also known as Olduvai Gorge). It is one of the most important prehistoric sites in the world. In the 1950’s to 1970’s Mary Leakey and her husband Louis discovered tools and fossils of ancient hominines. And it was there where Mary found the Laetoli hominid footprint trail which was left in volcanic ashes some 3.6 million years ago. We also visited the Oldupai Gorge Museum. This Museum presents exhibitions pertaining to the Gorge’s history.