The Aïr Mountains are a mountain island in the Sahara of northern Niger, nine ranges of granite towers and dark basalt domes spread over some 400 kilometres. They stand high enough to catch rain the desert around them never gets. What falls collects in shaded gullies as gueltas, rock pools that hold through the dry season and feed small palm oases. Tuareg salt caravans have crossed the range for centuries, watering at those pools, and you can ride between them by camel with guides who still read this desert. From the top of a basalt dome you see the ranges run away eastward, one behind another, into the haze of the Ténéré sand sea. Some of the near-perfect circular ridges up there are the roots of dead volcanoes, bared once the cones above wore away. One of them is about sixty kilometres across, among the largest on Earth.
Agadez, the old caravan city, stands at the foot of the mountains, where a sixteenth-century mosque raises the world's tallest mud-brick minaret over a maze of earthen houses. As the rains end, thousands of Tuareg and Wodaabe gather near In-Gall for the Cure Salée, with camel parades and races. At the centre of it is the Gerewol. Young Wodaabe men whiten their teeth and eyes, paint their faces deep ochre and dance for hours to be judged the most beautiful — by the women, who walk the line and choose. You sleep out in the open, hundreds of kilometres from the nearest electric light. Northern Niger sits under do-not-travel warnings, and you travel here only with a military escort arranged in Agadez. At Dabous, on the western edge of the massif, one outcrop carries two giraffes carved almost life-size, the larger 5.4 metres from hoof to head. They were cut six to eight thousand years ago, when this was grassland with herds on it. An engraved cord runs from its muzzle to a small human figure beside it.