Diyarbakır is home to the Hevsel Gardens used for agricultural purposes for more than 8,000 years, the Great (Ulu) Mosque, one of the oldest mosques of Anatolia, Malabadi bridge built by the Artuqid period in the 12th century, Hasuni Cave city in which pre-historic people inhabited during the early years of Christianity, Zerzevan Castle which is a Roman military facility containing templet of Mithraism, a mysterious religion.