El Oued or Oued Souf is a city in El Oued province, Algeria .. The oasis town is watered by an underground river, hence its name, which enables date palm cultivation and the rare use (for the desert) of brick construction for housing. As most roofs are domed, it is known as the "City of a Thousand Domes"[1].

El Oued is located 400 miles south east of Algiers (the capital city of Algeria), near the Tunisian border. It lies about 20 kilometres south of Guemar Airport. The population of El Oued was 139,362 as of the 1998 census.