Yuncheng is located in the southwest of Shanxi, known as Hedong in ancient times, is a prefecture-level city under the jurisdiction of Shanxi Province, and Yuncheng Salt Lake is called Hedong Salt Pond in ancient times. Yuncheng Salt Lake is the largest lake in Shanxi, the oldest inland salt lake in China, and is known as the world's three largest sodium sulfate inland salt lakes together with the Ogtin Salt Lake in Utah, USA, and the Kuchuk Salt Lake in Siberia, Russia.