The Kasbah of Marrakesh, built by the Almohad sultan Yaqub al-Mansour, is the site of the El Mansouria Mosque, the El Badi Palace and the Saadian Tombs. Bab Ksiba was the entrance to another small kasbah (ksiba or qusayba) which was adjoined to the southwestern corner of the main kasbah in order to protect the western side of the Grand Mechouar (a vast open square, still present today, at the entrance of the royal palace) and the Derb Chtouka neighbourhood.[1] The date of its construction is unclear; it existed at the beginning of the 19th century and may have been built under Muhammad ibn Abdallah in the 18th century, but was almost certainly not part of the original Almohad kasbah.[1]:501