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
Ly Erg Ly Erg The Ly Erg is a fairy from Scottish folklore, particularly associated with the area in and around the Glenmore Forest, part of the present-day Cairngorms National Park. It is dressed as a soldier, distinguishable from a real soldier only by its red right hand, said to be stained with the blood of its victims. While out walking it will stop near water, and by raising its right hand challenge passersby to fight. But anyone who engages in combat with the Ly Erg will be dead within a fortnight, win or lose. Writing in 1847, the antiquarian Joseph Robertson