Bab El-Khalq was established by King Saleh Najm El-Din Ayoubi in 1241 AD and includes many monuments from the Fatimid and Ayyubid eras, including mosques. The most famous mosque is "Al-Hakim bi-Amr Allah" which later became a museum of Islamic Arts. The large library which was established in 1870 AD holds many rare Islamic manuscripts.