Later Stone Age and Iron Age rock shelters with rock art, in northwest Botswana. Depression Shelter in the Tsodilo Hills has evidence of continuous Khoisan occupation from about 17,000 BC to about 1650 AD. There is also evidence of early farming settlement there, alongside Khoisan hunter and pastoralist sites, dated from about 550 AD. Archaeologists therefore have difficulty in interpreting the hundreds of rock paintings in the Tsodilo Hills, which were once assumed to be painted by Bushman (San) hunters remote from all pastoralist and farmer contact.