Who sold the salt pond in Yuncheng, Shanxi?

Not for anyone. According to official website, the Shanxi Provincial People's Government, Yuncheng Yanchi is located in Yuncheng City on the east bank of the Yellow River in southwest Shanxi Province. It was once a part of the ancient ocean. Due to crustal movement and land-sea changes, it rose to a platform and accumulated a large number of salt minerals on its surface. In addition, the climate here is dry and sunny, and after a long period of wind, rain and sun, salt keeps accumulating. Yuncheng salt pond has a long history of production. Salt production began in the Xia Dynasty as far back as 3000 years ago. By the Spring and Autumn Period and the Warring States Period, it had invented an artificial method of making salt-"ploughing, watering and drying". This method continues to this day and is called "mechanized salt making" instead of "selling it to others".