The first glimpse of Ouadâne, a Unesco World Heritage site is arresting. The old quarter that stretches atop the hill is one of the most enchanting semi-ghost towns of the Sahara. As you arrive across the sands or plateau from Atâr or Chinguetti, the stone houses of Le Ksar al Kiali (old quarter) seem to tumble down the cliff like an apparition.

From the base of the town, the lush gardens of the oasis stretch out before the desert again takes hold. The top of the hill is dominated by the minaret of the new mosque, a mere 200 years old. At the western end, at the base of the town, is the 14th-century old mosque.

Ouadâne was founded in 1147 by Berbers, and sits on the edge of the Adrar plateau. For 400 years, it was a prosperous caravan centre and a transit point for dates, salt and gold.

Like Chinguetti, Ouadâne was a place of scholarship and is home to over 3000 manuscripts held in 23, mostly private, libraries. There's also a small museum housing various artefacts from the ancient caravans.