Ouadane is a medieval Saharan city of the Adrar plateau in central Mauritania, founded around 1147 by three Berber clerics from the Sanhaja population — Sidi Abdellah ibn Bouzid, Sidi Sleimane, and Sidi Boukar — who established a religious school and a fortified settlement at the meeting point of two principal trans-Saharan caravan routes.
By the late medieval period Ouadane had become one of the principal entrepôts of west African trade, exporting gold, salt, dates, and books across the Sahara to Sijilmasa and Marrakesh and importing Andalusi cloth and Mediterranean manufactured goods. The Portuguese established a trading post at the site in 1487 — the first European factor on the western Sahara — although the position was abandoned within a generation.
The town declined from the seventeenth century onwards as the trans-Saharan economy contracted and successive Hassani Arab confederations displaced or absorbed the Berber populations of the western Sahara. The old quarter of Ouadane is now a partially abandoned ruin; the modern town adjoins it.
Ouadane was inscribed by UNESCO as part of the Ancient ksour of Ouadane, Chinguetti, Tichitt and Oualata serial World Heritage Site in 1996. It preserves one of the densest concentrations of medieval Berber-Saharan stone-and-mud architecture in north Africa, and the surviving private libraries hold substantial manuscript collections in Arabic and Zenaga Berber.