Susa was an ancient city of the Proto-Elamite, Elamite, First Persian Empire, Seleucid, Parthian, and Sasanian empires of Iran, and one of the most important cities of the Ancient Near East. It is located in the lower Zagros Mountains between the Karkheh and Dez Rivers. The site now consists of three gigantic mounds, occupying an area of about one square kilometer, known as the Apadana mound, the Acropolis mound, and the Ville Royale (royal town) mound.