To the north of the city of Djanet, the desert scenery is occupied by the spectacular rock face of the Tassili N’Ajjer, a sandstone plateau that runs parallel to the dune belt of the Erg Admer, heading south-east to the Libyan border. The Kel Ajjer mountain of the, the Tuareg tribe that inhabits the region, hides in its inaccessible meanders one of the most incredible treasures that the Sahara desert has ever yielded.

A cultural park, UNESCO heritage site and biosphere reserve, the Tassili, which is about 500 km long, looks like a compact sheer cliff, which can only be crossed on foot or on donkeyback, through a few sporadic natural passages that climb and creep up its sides. On reaching the top of the plateau, a world of extraordinary lunar scenery opens up, characterised by a dizzying maze of sandstone “forests”, stone deserts and labyrinthine canyons, monumental rock formations eroded by atmospheric agents, ravines and caves hidden among the stone backdrops carved by the numerous wadis that have now dried up. An incredible geological landscape that in turn hosts an extraordinary desert biodiversity, with the survival of some naturalistic species now extinct in the rest of the Sahara, such as the myrtle and the Saharan cypress.

But as the largest troglodyte site in the world, its uniqueness lies above all in the archaeological evidence of human settlements and civilisations that have followed one another over at least 10,000 years. With numerous lithic artefacts, mounds and concentric stone burials, and pottery from various periods, the Tassili N’Ajjer contains the highest concentration, stratification and iconographic variety of rock art ever found, with some 15,000 paintings and engravings currently listed. An immense ‘Sistine Chapel’ in the heart of the Sahara, as it is commonly called.