This is the largest wadi in the Arabian peninsula. Situated about 160km from the coast, it follows an east-west route for about 160km through the desert. The wadi bottom drops to a depth of about 300 metres.
The region is very fertile and the local population lives on arable farming and goat-herding. There are several archaeological sites in the region, which show signs of early settlement before the 3rd century A.D.