The Al Qal'a of Beni Hammad is an archeological site, which holds the first capital of the Hammadid empire. It was founded in 1007 and destroyed in 1152. The Qal'a (Fortress) is located at more than 1,000m altitude. The town includes a 7 km-long line of walls. Inside the walls are four residential complexes, and the largest mosque built in Algeria after that of Mansurah. The remains of the emir's palace, known as Dal al-Bahr, include three separate residences separated by gardens and pavilions