Grand Erg Oriental follow the wind's direction. There are other types of dunes, as well as "complex" dunes. Saharan winds are also known to clear an area of sand altogether, leaving bare rock (hamada) or gravel (reg). The "Grand Erg Oriental" is accessible overland by an Algerian road, which goes south from Constantine. It passes through the Aurès mountains, then salt lakes by the city of Biskra. Next the road skirts the western edge of the erg. After about 500 km. in all, it reaches the ancient oasis of Ourgla [Wargla]. Since late antiquity Wargla was a stop for the Saharan trade, being
Erg Ferradj are generally well provided for. 100% of Erg Ferradj's population is connected to drinking water, 99% is connected to the sewerage system, and 99% (including 756 buildings) have access to electricity. There is no fuel service station in the town. Erg Ferradj has a total of 1,300 houses, of which 712 are occupied, giving an occupation rate of 6.2 inhabitants per occupied building. Erg Ferradj is reached by a local road from the N6 highway just west of Abadla. It is from Abadla and from Béchar. There is a total length of of roads in the commune. There are 3