It looks like a gigantic stone school board. In the Doro Nawas Mountains of Namibia stands a sandstone block, around ten meters wide, around five meters high and covered with engraved images. Here, human hands have hammered outline drawings of elephants, giraffes and people into the rock and engraved hundreds of footprints, of cats and rhinos, birds and even-toed ungulates. The images are difficult to date; they are probably several thousand years old. One might think that prehistoric hunters and gatherers would have used them to teach their offspring how to track.
Archaeology: Mysterious artificial footprints discovered in rock faces in Namibia – Knowledge
