Introduction to Heiniu Salt Well: In the late Neolithic Age 4,000 years ago, A Zhao, a Yi woman, under the guidance of Heiniu, discovered that a brine spring naturally overflowed at the foot of the river and the mountain. From then on, the ancestors of Heijing collected brine for food; in the Bronze Age, they dug ponds to store brine and used the primitive firewood method to make salt; during the Nanzhao period, they dug ponds to collect brine and used cauldrons to fry the salt, and Heijing salt became tribute salt exclusively for the royal family. In the Yuan Dynasty, the central government set up Weichu Luti to take charge of the salt transportation department of black salt wells. But in these two thousand years, only two or three salt wells were dug in Heijing.