Structurally, the Adrar is a low central massif. East of the town of Atar, near the Amojjar Pass on the old caravan track to Chinguetti, it climbs to more than 700 meters above sea level before losing its nerve, sloping away, and surrendering to the dunes that swallow its southern and eastern edges. The surface is a study in textures: regs, the stony pavements polished by wind, give way to canyons cut by long-dead rivers, which give way again to seas of sand. It is a landscape built by water and then abandoned by it - a place still shaped by a climate it no longer has.

Almost nothing grows on the open plateau, but in the gorges the story changes. In low valleys like the oued Seguellil, the water table rises close enough to the surface to sustain real life, and the desert relents. Here you find date palm groves, dense and dark green, sheltered between sandstone walls that hold back the wind. These pockets of cultivation are why the Adrar was ever habitable at all - thin ribbons of orchard threaded through hundreds of kilometers of stone and sand, each one an oasis in the most literal sense.

People settled the Adrar in the Neolithic, and they left their gallery on the rock. At sites such as the Agrour Amogjar, ancient hands painted and carved scenes onto stone walls - a record of a Sahara that was once green, grazed by animals that could never survive here now. Scattered across the plateau stand stone circles raised by these early inhabitants, including the one near Atar. It is one of the desert's quiet ironies that aridity, which makes life so hard, also preserves the past: with so little rain to erode them, these monuments and paintings have endured for thousands of years, untouched.

Later, the Adrar became a crossroads. Caravans crossing the Sahara funneled through its passes, and along their routes rose trading towns that grew rich on salt, gold, and the long memory of the desert roads. The ksour - the old fortified towns - of Chinguetti and Ouadane cling to the plateau's flanks, and together with Tichitt and Oualata they form a UNESCO World Heritage Site honoring the medieval Islamic culture that flourished here. Near Atar lie the ruins of Azougui, remembered as a cradle of the Almoravid movement that would one day reach across North Africa and into Spain.

To stand on the Adrar is to read deep time written in stone. The cliffs hold the bones of an ancient seabed. The dry gorges remember rivers. The rock art remembers grasslands and game. The ruined towns remember caravans and scholars. Each layer is older than the last, and the desert has preserved them all because the desert, for all its cruelty, forgets nothing. A henna-stained hand, a stone cairn marking a path, a postbox at the little airport in Atar - the human present is just the thinnest, newest layer on a landscape that has been keeping records for ten thousand years.