A man and his yak are seen on the bank of the Yamzho Yumco Lake in Shannan Prefecture, southwest China's Tibet Autonomous Region, Oct. 25, 2015. The 638-square-kilometer lake locates on an altitude of 4410 meters at the Qinghai-Tibet Plateau. Yamzho Yumco, which in Tibetan means a "jade lake" on high pasture, is considered as one of the three sacred lakes in Tibet (the other two are Nam Co and Mapam Yumco). (Xinhua/Zhang Rufeng)