Huge massive mountains pop up in the middle of the Sahara: they are Ahnet, Mouydir, and Hoggar. The gorges of Arak, having been dug into rocks, allow us access to the hearts of these mountains. Up above, the granite rocks endure a slow disentegration. The center of Hoggar (reaching up to 3,000 meters of altitude) is nothing but a rocky chaos. Volcanic eruptions have also caused some basaltic flows from which the debris came that now covers the mountain slopes. A difficult and formidable region stretches towards Sudan: the TANEZROUFT, or the Land of Thirst; void of water and vegetation for over 500 kilometers. The Adrar of Iforas belongs to Sudan. These mountains appear to be buried in their own debris, the chemically formed black sheen of which is called "varnish of the desert." Kidal's post, in the Adrar, and his camp of infantrymen. Tam-Tam with the infantrymen. The Bourem fort, near the Niger (river). "Djoliba! Djoliba! (The Niger, The Niger)" thus are the cries of the natives when, after the difficult desert crossing, they first see the river.