Mapam Yumco is one of the three sacred lakes in Tibet, lies 20 km southeast of Mt Kailash and is north to Namnani Peak. It is the highest freshwater lake in the world. With an altitude of 4,588 meters, the lake covers an area of 412 sq. km and has a maximum depth of 70 meters. In Tibetan language, Mapam Yumco means the "eternal and invincible jade lake", named to mark the victory of Buddhism over the local Bon Religion in the 11tth century. Mapam Yumco Lake has been mentioned in many religious records and legends. In Buddhist scriptures, the lake is regarded as the "mother of rivers in the world". Buddhists believe that water in the lake can wash away "five malignancies of the human soul" and can remove filth from human skin and purify the soul. So many people come here to take a bath and even carry samples of water from the holy lack back home for relatives and friends.