Azerbaijan or Azarbaijan also is known as Iranian Azerbaijan, is a historical region in northwestern Iran that borders Iraq, Turkey, the Nakhchivan Autonomous Republic, Armenia, and the Republic of Azerbaijan. Iranian Azerbaijan is administratively divided into West Azerbaijan, East Azerbaijan. The region is mostly populated by Azerbaijanis, with minority populations of Kurds, Armenians, Tats, Talysh, Assyrians, and Persians. Iranian Azerbaijan is the land originally and historically called Azerbaijan; the Azerbaijani-populated Republic of Azerbaijan appropriated the name of the neighboring Azerbaijani-populated region in Iran during the 20th century. Historic Azerbaijan was called Atropatene in antiquity and Aturpatakan in the pre-Islamic Middle Ages. The region is mountainous, with most of the area situated over 1000m above sea level and many peaks exceeding 3000m in height. Lake Urmia, a shallow salt lake some 5000 square km in area, is sandwiched between West and East Azerbaijan provinces and is Iran's largest lake after the Caspian Sea