They left behind tools, as well as traces of meals and shelters. In the lowest levels pebble tools have been found and, in the higher levels, men of the Middle and Late Stone Age have left many examples of beautiful two-edged hand-axes, obsidian scrapers, and sets of ‘bolas’ – the round stones used together in nets to throw at animals. Fossilized bones of hippopotamus, rhinoceros, elephant, and various antelope have also been found here.
If you walk upstream along the banks of the river, some of these Stone Age tools can often be seen, particularly in the dry washes. Remember, however, that collecting of Stone Age artifacts is prohibited, and local citizens help to enforce this restriction.