Ben Amira is Africa's largest monolith rising 633 meters (2027 ft) above the desert floor. It's the world's second largest monolith only behind Uluru, in Australia. It is located in the Adrar region, near the border with Western Sahara, some 400 km far from Nouakchott. It lies 4 km north of the train track where the famous Iron Ore Train travels between Nouadibhou and Choum.

​

Nearby, a lesser monolith, Aïsha lies a 20-minute drive to the west of Ben Amera. In 1999, a dozen artists of international fame celebrated the millennium by carving into the boulders at the base of Aïsha. They etched deep into the stone creating animal shapes as well as abstract. Some of the artworks are installation pieces that go beyond the boulder’s surface and use multiple stones in specific configurations to create their effect.