site of paleoanthropological excavations carried out since the late 1960s within a complex of South African coastal caves. Usually referred to as Klasies River Mouth, the site has yielded some of the oldest evidence of Homo sapiens.

Discoveries made at Klasies have figured prominently in the search for the origin of modern people. The human remains, tools, and other evidence of human activity found there may date as far back as 120,000 years ago. Although the material is fragmentary, enough of it is preserved to show that the people who lived there were essentially modern, unlike Neanderthals or other archaic humans (genus Homo). The denizens of Klasies possessed prominent chins, modern faces, and limb bones like those of modern humans.

In the oldest archaeological layers are flake-based Middle Paleolithic (Paleolithic Period) tools traditionally referred to as African Middle Stone Age. At about 70,000 years ago a blade-based industry called Howieson's Poort begins; this industry is a precursor of Upper Paleolithic technology. Analysis of animal remains found at the site reveals some of the earliest evidence of humans' making use of marine resources such as shellfish.