On the bor­ders of Tas­sili N‘Ajjer in Alge­ria, also a World Her­itage site, this rocky mas­sif has thou­sands of cave paint­ings in very dif­fer­ent styles, dat­ing from 12,000 B.C. to A.D. 100. They reflect marked changes in the fau­na and flo­ra, and also the dif­fer­ent ways of life of the pop­u­la­tions that suc­ceed­ed one anoth­er in this region of the Sahara.