Aerial photo taken on May 4, 2020 shows salt pans in Naxi Township of Mangkam County, southwest China's Tibet Autonomous Region. Making salt by evaporating brine in the sun dates back to the Tang Dynasty(618-907 AD) by the Lancang River in Mangkam. The traditional techniques of airing salt were passed down and preserved at the salt pans in the county. (Xinhua/Wang Zehao)
