also called El-Boulayda, an Algeria Administrative and trading center on the Algiers-Oran rail route. It lies 48km (30 miles) south-west of Algiers on the Mitidja Plain, in the middle of a citrus-growing area. It also has some light industry and manufactures flour, olive oil and soap. The Wadi el-Kebīr, an affluent of the Wadi Chiffa, supplies water for fountains and gardens in the town and is a source for hydropower.

Blida, diminutive of the Arabic balad, "city" occupies the site of a Roman military station. Formerly walled with six gates, the present town was founded in 1553 by Moorish refugees from Andalusia. A mosque was built in the town by order of Khayr ad-Din (Barbarossa). Blida was severely damaged by earthquakes in 1825 and 1867. It is overlooked (south) by the ruined Fort Mimich. Mount el-Mergueb (5,344 feet [1,629 m]), Chiffa Gorge, and Chrea mountain and ski resort are nearby. Crops grown in adjacent areas of the Mitidja plain include wheat, barley, citrus fruits, vegetables, tobacco, and olives. There are also vineyards in the area.

Population: (estimated) 220.000