The dunes start a few kilometres west of town and continue, without interruption, for the next 400 kilometres. From the edge of the oasis the view is almost cartoonish — a clean line where the green of the palms meets a sea of red-gold sand, with no transition and no horizon line beyond.
A short walk up the first dune at sunset is the usual programme. With a 4WD and a guide you can go further into the erg for a night under the stars, which is what most organised tours arrange. The silence and the scale are the point; there is nothing else out there.