The old city of Algiers is located in the area of the youngest structure on the African continent consisting of the folding chain of the Tell Atlas. It is arranged in a triangular amphitheater whose base runs along the Mediterranean Sea and the summit reaches the Qasbah, citadel of Algiers; a disposition that shelters it from attacks and external threats for a long time. This defensive position is reinforced by a very deep ditch located on the sides of the triangle and on the side of which stood high and solid stone walls forming the ramparts of the city. The narrations of travelers, historians and soldiers evoke the splendor and resistance of these works and constitute an undeniable source in the recognition of the defensive system of the old city at that time. This said, the discovery of very interesting archaeological traces during the consolidation of part of the walls of the Qasbah “citadel of Algiers” on the side of the battery 4 is an essential element in the commitment to a reflection on the development of the defensive system of Algiers . As well as the different phases of construction of the wall of the city (at least in the eastern part), based on tangible physical evidence.
Keywords: The Old Algiers’s Wall, Defensive System, Citadel of Algiers.