A cave complex south-west of Beijing, made famous by fossils of Peking Man. The fossils are believed to represent a Chinese variant of Homo erectus (Homo erectus pekinensis). More than 40 male and female Homo erectus individuals are now known from the caves. Added to this hominid collection are many tens of thousands of simple flaked stone tools as well as fossilized bones of more than 100 animal species and so-called ash layers that were once interpreted as cooking hearths. The caves were occupied by Peking Man from about 500,000 to 250,000 years ago.