Khara-Khoto

Khara-Khoto, also known as Qara-Qoto, Heishuicheng or Heishui City, is an abandoned city in the Ejin Banner of Alxa League in western Inner Mongolia, China, near the Juyan Lake Basin. Built in 1032, the city thrived under the rule of the Tangut-led Western Xia dynasty. It has been identified as the city of Etzina, which appears in The Travels of Marco Polo, and Ejin Banner is named after this city.

Source: Wikipedia