At Koobi Fora, there are archaeological sites with evidence of control of fire by "Homo erectus" 1.5 million years ago, with the reddening of sediment that can only come from heating at 200—400 °C. There is a hearth-like depression at a site in Olorgesailie, Kenya. Some very tiny charcoal was found, but it could have come from a natural brush fire.