On the east­ern slopes of the Masai escarp­ment bor­der­ing the Great Rift Val­ley are nat­ur­al rock shel­ters, over­hang­ing slabs of sed­i­men­ta­ry rocks frag­ment­ed by rift faults, whose ver­ti­cal planes have been used for rock paint­ings for at least two mil­len­nia. The spec­tac­u­lar col­lec­tion of images from over 150 shel­ters over 2,336 km² , many with high artis­tic val­ue, dis­plays sequences that pro­vide a unique tes­ti­mo­ny to the chang­ing socio-eco­nom­ic base of the area from hunter-gath­­er­er to agro-pas­­toral­ist, and the beliefs and ideas asso­ci­at­ed with the dif­fer­ent soci­eties. Some of the shel­ters are still con­sid­ered to have rit­u­al asso­ci­a­tions with the peo­ple who live near­by, reflect­ing their beliefs, rit­u­als and cos­mo­log­i­cal tra­di­tions.