Olorgesailie: of Bones, Birds and Bandas

It is known as the ‘place of the spirits’. It is also, according to a few who have stayed the night there, one of the only places in the country that is so quiet that you can really hear the sound of silence in the dead of the night. I am talking about Olorgesailie – the wide, shallow lake basin 70km south of Nairobi, wedged between two extinct volcanoes on the southern edge of Kenya’s Rift Valley. Since the freshwater in the basin disappeared 180,000 years ago, thousands of years’ worth of natural erosion has exposed a huge concentration of carved stone ‘hand axes’ – used by early humans who lived by the lakeshore between 500,000 and one million years ago. The preservation of these ancient tools, as well as a number of animal fossils, has made the site a popular stopover for travellers en route to the alkaline waters of Lake Magadi further south.

A few Sundays ago, undeterred by the heavy rain, we decided to make the journey to Magadi, and paid the site a visit on the way. Instead of taking the direct route through Rongai, we opted for the more scenic road past the Ngong Hills, and through Kiserian. The Magadi Road was once considered the best road in the country, but at the moment it is probably one of the worst. You spend most of the journey driving sideways to avoid the potholes, and the section between Kiserian and the turnoff to Olorgesailie is particularly bad. At least it gives you more time to appreciate the scenery, if that’s any consolation.

The turnoff is well signposted, about 3km south of Oltepesi, after which you travel a short distance on a track through the thick white silt that is characteristic of the area. This leads to the museum, bandas and camping area, which sit just above the main excavation sites on a ridge overlooking the wide lake basin. Though the museum is small, it is very informative, and displays a variety of hand axes, rounded stone balls and animal fossils discovered in the area. These tools belonged to a species of hominid, most likely Homo Erectus, who inhabited the lakeshore between 400,000 and 500,000 years ago.

According to Andrew, our guide and the museum’s curator, the tools were mainly used for skinning and cutting meat off the animals they hunted. One of the displays compares hand axes from all over the world, including a flint axe from Egypt and a quartz axe from the Olduvai Gorge in Tanzania. Another explains why these tools are so well preserved – due to heavy falls of alkaline volcanic ash from Mt. Suswa and Mt. Longonot. Though fragments of human fossils were also discovered at the base of the nearby Mt. Olorgesailie, they aren’t displayed at the site, and instead form part of the excellent early man exhibit at the National Museum in Nairobi.

Once we had finished the tour of the museum, Andrew led us round some of the main excavation sites. The first discovery of hand axes at the site, he explained, was made in 1919 by the British geologist, John Walter Gregory. It was Mary and Louis Leakey, though, who carried out most of the unearthing in the 1940s, as well as the South African archaeologist Glynn Isaac in the 1960s, and Richard Potts of the Smithsonian Institute in the 80s. According to Andrew, Richard Potts still visits the site every year to carry out research for the institute’s Human Origins Programme.

Thousands of stone tools that he and the other researchers unearthed have been left undisturbed under protective mabati roofs. The one exception is ‘The Catwalk’, which is a boardwalk over a large collection of exposed hand axes unearthed by Dr Mary Leakey – the discovery that triggered more extensive research in the 1940s. I asked why there were so many tools. Allegedly, the early humans who carved them always left them behind wherever they killed an animal, and made new ones before they went out to hunt again – recycling wasn’t a concept that they had figured out yet. Amongst the collection of tools are what the guides claim to be small chippings from the hand axes, though they were very difficult to distinguish from every other small stone in the area.

As well as the hand axes, some of the excavations unearthed the remains of a variety of animals, some of which the early humans had presumably hunted. The most impressive of these, by a long way, is the 992,000 year old fossilised humerus (upper arm bone) of an elephant. The bone on display is one of the last of that particular species of elephant, which became extinct about 600,000 years ago. The humerus from a modern elephant has been placed next to it to illustrate just how big the elephant was.

If looking at fascinating fossils isn’t your cup of tea, you can camp or stay in a banda at the site and hike up Mt. Olorgesailie – one of the two extinct volcanoes on either side of the lake basin. It is also great for bird watching.

Published in Kenya’s Sunday Nation

(Photo: http://www.theeastafrican.co.ke)