Lake Gurudongmar is one of the highest lakes in the world and is located at an altitude of 17,800 feet in the Indian state of Sikkim. It is considered sacred by Buddhists, Sikhs and Hindus. The lake is named after Guru Padmasambhava, also known as Guru Rinpoche, the founder of Tibetan Buddhism who visited in the eighth century.

The lake, which is fed by glaciers, is located north of the Kangchenjunga Range, in a high plateau area connected to the Tibetan Plateau. It provides one of the source rivers that joins the Tsu Lahmo and then the source of the Teesta River. The lake is completely frozen during the winter months November-May.

The lake is freshwater and was very clean. The bed of the lake could also be seen from the middle of the lake. Pollution has polluted the water in recent years, and the lake has turned white, obscuring visibility.