Sidi Bel Abbès, town, northwestern Algeria, on the Wadi Mekerra in the Tell Atlas Mountains. Named for the tomb of the marabout (saint) Sīdī Bel ʿAbbāss, it was established as a French military outpost in 1843 and became a planned agricultural town in 1849. Sidi Bel Abbès was the headquarters of the Foreign Legion, whose barracks once housed the Legion Museum. After Algerian independence in 1962 all French troops and legionnaires were evacuated from the town, and the Legion Museum was transferred to Aubagne, France. The old walls and bastions were demolished in the 1930s and have been replaced by wide boulevards and squares, beyond which are spreading suburbs. Industry includes a farm-machine manufacturing complex. The surrounding area, once swampy, now produces cereals (mainly wheat and barley) and grapes. Pop. (1998) 180,260; (2008) 210,146.