Grand Erg Oriental small but ancient settlement of Ghadames at the Libyan frontier. Another and better road from Hassi Messaoud goes south, also crossing the grand erg where it passes a well called "Hassi Tartrat", before reaching the erg's far side. Further south lies the Ahaggar mountains. The cities of Wargla and Touggourt lie outside the western limits of the erg. Nearby, within the accepted boundaries of the "Grand Erg Oriental", the landscape is described as being "practically free from [sand] dunes" evidently due to strong, persistent winds. Petroleum and other hydrocarbons have been extracted in Algeria, from areas in and surrounding the
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