Introduction to the ancient salt well: In the Hongwu year of the Ming Dynasty, Heijing established a salt class promotion department of the fifth grade, which was directly under the jurisdiction of the province. The central government moved 64 extraordinary Zaoding people from Yingtian Mansion to vigorously develop Heijing. After hundreds of years of development, by the Qing Dynasty, the Heijing Salt Industry reached its peak, and the salt tax accounted for 64% of the Yunnan salt tax. Before liberation, Heijing set up a field affairs office, but the "invasion" of Haiyan caused the once-rich Salt City to decline due to the loss of its pillars.