Erg Chebbi is a sea of wind-built sand on the far western edge of the Sahara, where single dunes climb as high as 150 metres above the flat, stony desert around them. It is one of Morocco's two great ergs, a range of orange sand about 22 kilometres long that runs south along the Algerian border, its crests endlessly reshaped by the wind. On the dunes' western edge sits Merzouga, a village that grew up on the trans-Saharan caravan trade — the ruined city of Sijilmassa, gateway of the medieval gold-and-salt road to Timbuktu, lies a short way north near Rissani. And in wet winters a shallow salt lake, Dayet Srji, fills just west of the village and pulls flamingos and migrating birds into the desert, though in dry years it never appears at all.
The classic way in is on a camel, setting out across the sand in the late afternoon as your shadow stretches long behind you and the heat begins to fade. You spend the night at a tented camp between the ridges, where Berber drums give way to a silence so complete you notice it, and the sky fills from edge to edge with stars in air free of any city glow. Climb the highest dune before dawn to watch the sun set the whole erg alight; by day you can sandboard the steep faces or cross the sand by 4x4. In the hottest months locals still bury visitors neck-deep in the sun-heated sand for a few minutes, an old folk cure for aching joints. Merzouga is easy to reach now, with sealed roads and dozens of camps along the dunes, but walk a ridge or two beyond the lights and the desert is as silent as it ever was.