The citadel is located in the northwest corner of the old walled city of Damascus, between the Bab al-Faradis and the Bab al-Jabiyah. Whereas most medieval Arabic castles are located on prominent hilltops, the citadel of Damascus was built on flat ground at the same level as the rest of the city, a feature it shares with the Citadel of Bosra. The location of the citadel ensured that it could control the Barada River, which flows north of the citadel. The location of the river also offered protection against attack from that side of the citadel. The Nahr Aqrabani, a canal branching off the Barada, flowed immediately below the northern wall and provided additional protection. The dry moats on the other sides of the citadel could be filled from these streams. Another branch of the Barada, the Nahr Banyas, entered the city under the citadel. Hydraulic structures below that made control of the flow of water into Damascus possible from within the citadel were probably constructed under Al-Adil. The citadel was fully integrated into the defences of Damascus, with the city walls abutting the citadel on its southwest and northeast corners.