Twyfelfontein valley has been inhabited by stone- age hunter- gatherers of the Wiltton stone- age culture group since approximately 6,000 years ago. They made most of the engravings and probably all the paintings. 2,000 to 2,500 years ago the Khoikhoi, an ethnic group related to the San (Bushmen), occupied the valley, then known under its Damara/Nama name lUillAis (jumping waterhole). The Khoikhoi also produced rock art which can clearly be distinguished from the older engravings. While commonly being translated as doubtful spring, a mor3e accurate translation for the word twyfel is there-fore “questionable “or “ uncertain”.