Photo taken on Feb. 8, 2017 shows salt evaporation ponds during sunset in Yuncheng City, north China's Shanxi Province. These ponds are rich in natural salt resources that were first explored 3,000 years ago. (Xinhua/Yan Xin)
Photo taken on Feb. 8, 2017 shows salt evaporation ponds during sunset in Yuncheng City, north China's Shanxi Province. These ponds are rich in natural salt resources that were first explored 3,000 years ago. (Xinhua/Yan Xin)