El Oued, also known as Souf or Oued Souf, is an oasis town located in Algeria. It serves as the capital of the El Oued Province.
The city is situated around an underground river that provides the water necessary for extensive date palm cultivation. Due to its unique geography and resources, the area features a distinct architectural style characterized by the use of brick construction for housing. Because many of these roofs are shaped into domes, El Oued is commonly referred to as the "City of a Thousand Domes."