The range is also noted for its prehistoricrock art and other ancient archaeological sites, dating from the Neolithic era when the local climate was less dry, savannah rather than desert. The art is no older than 9–10 millennia, according to OSL dating of associated sediments, but may be younger. The art depicts herds of cattle, large wild animals including crocodiles, and human activities such as hunting and dancing. According to UNESCO, "The exceptional density of paintings and engravings...have made Tassili world famous as from 1933, the date of its discovery. 15,000 engravings have been identified to date."
The plateau is also of great geological and aesthetic interest: the panorama of geological formations with "rock forests" of eroded sandstone resembles a strange lunar landscape.
The range is composed largely of sandstone. Erosion in the area has resulted in nearly 300 natural rock arches being formed, along with many other spectacular landforms.
Because of the altitude and the water-holding properties of the sandstone, the vegetation here is somewhat richer than in the surrounding desert; it includes a very scattered woodland of the endangeredendemic species Saharan Cypress and Saharan Myrtle in the higher eastern half of the range.
In his 1992 book Food of the Gods, new-age icon Terence McKenna hypothesized that the Neolithic culture that inhabited the site used psilocybin mushrooms as part of its religious ritual life, citing rock paintings showing persons holding mushroom-like objects in their hands, as well as mushrooms growing from their bodies.
Tassili Plain is a track on the 1994 album Natural Wonders of the World in Dub by dub reggae group Zion Train.