Assekrem is a plateau at 2,726 metres in the Hoggar mountains of southern Algeria, in Tamanrasset province, ringed by black volcanic spires and needles that stand out of the Sahara like the ruins of a city, with a hermit's stone chapel of 1911 on its summit, and it is driven up to from Tamanrasset for the sunrise, held on the eastern rim while the light works across the field of spires for a full twenty minutes. The Hoggar is the core of an old volcanic range, and the Atakor around Assekrem is its highest part, a landscape of plugs and lava columns worn out of the desert, with Tahat, the highest peak in the country, among them; Charles de Foucauld, a French officer turned hermit, built his retreat of dry stone on the summit in 1911 and lived among the Tuareg for eleven years, making almost no converts and writing instead a dictionary of their language, and the Little Brothers of Jesus who keep his house open it to whoever has walked up the last kilometre from the road. The hut beside the hermitage is a station where the world measures its air, one of the global network sampling the atmosphere far from any source of pollution.
At dusk the skyline drops back to silhouette against a fading orange band and the sky fills, since there is no light for a hundred kilometres, and the guesthouse below the summit puts visitors up for the night between the sunset and the dawn. Most people drive up in a four-wheel drive over the rough track, but the Atakor is also walked, on treks of several days on foot and by camel with Tuareg guides between the gueltas, the rock pools that hold water in the valleys, and in winter the Sahara freezes here, with nights below zero, ice on the pools and in some years snow on the black spires. Tamanrasset is the Tuareg capital of the south and the base for everything. Assekrem is a hermit's rooftop in the desert, and the dawn from it is his view.