Known in ancient times as the "Pure Sea" or "Heavenly Lake", Sayram Lake is the highest and largest alpine lake in the Tianshan Mountains. It is located in Bole City, within the Bortala Mongol Autonomous Prefecture of Xinjiang. Famous for its crystal-clear waters, it is one of the most transparent lakes in China. As the final stop of the Atlantic warm and humid air currents, it is poetically called "the last tear of the Atlantic Ocean".