Kariandusi is a Palaeolithic site on the eastern edge of the Rift Valley, about 15 kilometres north of Naivasha town near the village of Gilgil. It is one of the best places in Kenya to see Acheulean stone tools — the teardrop-shaped hand axes that were the Swiss Army knife of the Stone Age — in context. The site is small and easily managed in an hour.
The open-air museum has an excavation trench showing the deposit as it was found, with tools left in situ for viewing. A small shelter houses a display of the site's history and the tools removed during excavation, including large obsidian hand axes of impressive workmanship. The setting — a low cliff above a dry valley with views toward the Rift Valley escarpment — is pleasant.
Kariandusi is on the A104 highway between Naivasha and Gilgil. Any matatu running north from Naivasha will pass the junction; ask to be dropped at Kariandusi. The site is administered by the National Museums of Kenya and charges a small entrance fee.