It was built up in 1880. Lachung implies a 'little mountain'. Lachung is at a rise of around 3,000 m at the juncture of the Lachen River and Lachung River, tributaries of the Teesta River. Lachung Monastery is a Nyingma Buddhist gompa in the Lachung Valley, Sikkim, northeastern India. The word Lachung signifies "little mountain".
The town is 118 km from Gangtok on the North Sikkim Highway and is the last one preceding the Indo-Chinese outskirt. It was an exchanging post amongst India and Tibet before China forcefuly added Tibet in 1950. Licenses are required for visits to North Sikkim. The religious community has an acclaimed cover move every year.