Huge ochre-coloured walls surround the Great Mosque, which was built in the 7C and is considered to be one of the oldest in the Maghreb. Its large courtyard is surrounded by a beautiful colonnaded arcade. The three-storey minaret stands in one corner, while two doors open into the prayer hall (access for Muslims only), which is adorned with white, pink and blue columns. This room contains the finely sculpted mihrab and minbar, which were made during work carried out by the Aghlabids in the 9C.