The lake, named Basum-Tso in Tibetan, is a highland lake lying 90 kilometers (56 miles) west of Kongpo Gymdo county. Basum has another Tibetan name, Tsokou, which means green water in Tibetan. Many glaciers on the upper reaches of the lake provide it with sufficient water supply. Covering 26 square kilometers (10 square miles), the clean green lake, reflecting snow capped peaks in the water, has so beautiful scenery that it makes one feels in Swiss. Fish are shoaling in the water; birds are circling in the air; beasts are roaming in the woods. Animals are living a comfortable and easy life in Basum. In 1997, the lake was listed by World Tourism Organization as a world tourist site.

Basum is a notable holy lake of Nyingmapa order of Tibetan Buddhism. On the northwest bank of the lake, there is a gigantic stone, which has a hole allowing one person to pass. Passing through the hole is said capable of relieve diseases and misfortunes. As a result every year many people come to visit the lake. At the center of the lake, on an islet there is a monastery, which was founded in the 17th century. The monastery mainly houses Maitreya and Chenrezi. Monks of the monastery bothered to carve all the reefs on the islets into Buddhist figures and animals.