Khwarazm (/xwəˈræzəm/; Old Persian: Hwârazmiya; Persian: خوارزم, Xwârazm or Xârazm) or Chorasmia (/kəˈræzmiə/) is a large oasis region on the Amu Darya river delta in western Central Asia, bordered on the north by the (former) Aral Sea, on the east by the Kyzylkum Desert, on the south by the Karakum Desert, and on the west by the Ustyurt Plateau. It was the center of the Iranian Khwarezmian civilization, and a series of kingdoms such as the Afrighid dynasty and the Anushtegin dynasty, whose capitals were (among others) Kath, Gurganj (now Konye-Urgench) and – from the 16th century on – Khiva. Today Khwarazm belongs partly to Uzbekistan and partly to Turkmenistan.