The Klasies River Caves are a series of caves located to the east of the Klasies River mouth on the Tsitsikamma coast in the Humansdorp district of Eastern Cape Province, South Africa. The three main caves and two shelters at the base of a high cliff have revealed evidence of middle stone age-associated human habitation from approximately 125,000 years ago. The 20 metres (66 ft) thick deposits were accumulated from 125,000 years ago.