The Phensang Sangag Chhoding monastery is located about a kilometer uphill by a road that bifurcates from the North Sikkim Highway. This is one of the six biggest monasteries having largest number of monks in Sikkim. The 3rd Lhatsun Jigmed Pawo (1682-1735) while travelling to Northern zone in 1721 A.D. founded this monastery.Later, it was rebuilt in 1840 to accommodate the large number of monks.

But unfortunately, it was gutted by fire in 1947 and was reconstructed it in following year. However, a torrential rain in 1983 badly damaged the structure again and repair was not a  feasible solution. Therefore, the Lamas dismantled the Structure completely and started rebuilding the monastery in 1985 with government aid, and brought it to full completion in 1996. As for mural painting works, it was recommended to Tourism Department who took up to care of the remaining works with the help of Central Government assistance under refurbishment of monasteries scheme. The monastery belongs to Nyingmapa Sect and performs all the major ceremonies with annual mask dance.