Photos taken show primitive salt pans in Markam County, Southwest China’s Tibet Autonomous Region on April 9, 2019. Originating from more than 1,200 years ago, the mode of production of salt here is unique and the most primitive in the world. People fetch brine from salt wells about several meters deep and dump it into salt pans. They get salt grains when the brine is dried in the sun. (Photos: VCG)