Lhalu wetland, "the Lung of Lhasa" in China's Tibet

People take a walk at Lhalu wetland in Lhasa, southwest China's Tibet Autonomous Region, on April 7, 2019. Lhalu wetland national nature reserve, with an altitude of 3,645 meters, covers an area of 12.2 square kilometers and is known as "the Lung of Lhasa." (Xinhua/Zhang Rufeng)