Grand Erg Occidental The mean elevation of the Grand Erg Occidental is about 500 m, on average higher than the elevation of the Grand Erg Oriental, but not as high as the neighboring Tademaït to the southwest. This desolate region is a practically uninhabited area; there are no permanent villages and there are no roads crossing it. Grand Erg Occidental The Grand Erg Occidental (, al-ʿIrq al-Gharbī al-Kabīr), (also known as the Western Sand Sea) is the second largest erg in northern Algeria after the Grand Erg Oriental. It covers an area of approximately . The sand dunes in the erg are formed
Grand Erg Oriental northern oasis on a Trans-Saharan trade route. South of Wargla on this road, lies Hassi Messaoud ["blessed well"], which is located within the "Grand Erg". Until recently Hassi Messaoud was a small Saharan village, but has grown substantially on account of the local discovery of oil in 1956. An oil refinery has since been built, and the city (current population estimated at 60,000) is now served by an international airport. A desert road going east from Hassi Messaoud continues through the "Grand Erg", passing by a well named "Bordj Sif Fatima" ["Fatima's River Tower" perhaps], on its way to the