one of the oldest streets in Cairo, approximately one kilometer long. A United Nations study found it to have the greatest concentration of medieval architectural treasures in the Islamic world. The street (shariʻa in Arabic) is named for Al-Muʿizz li-Deen Illah, the fourth caliph of the Fatimid dynasty. It stretches from Bab Al-Futuh in the north to Bab Zuweila in the south