El Oued (Arabic: اﻟﻮادي, Berber languages: Suf meaning the River), Souf or Oued Souf is a city, and the capital of El Oued Province, in Algeria. The oasis town is watered by an underground river, hence its name is El Oued 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".
El Oued is located 400 miles (640 km) south east of Algiers (the capital city of Algeria), near the Tunisian border. The population of El Oued was 134,699 as of the 2008 census, up from 105,256 in 1998, with a population growth rate of 2.5%
The inhabitants are thought to be Teroud tribe (Arabic: بنو طرود) living in and near Oued Souf area, however it is more likely that modern day Soufis are descendants of the original inhabitants of the oasis.
El Oued has a hot desert climate (Köppen climate classification BWh), with very hot summers and mild winters. Rainfall is light and sporadic, and summers are particularly dry.