Tendong Lho Rum Faat is one of the oldest festivals of the Lepchas and is usually held in August. The 3 day celebrations begin with the offering of prayers to Mount Tendong in South Sikkim. Legend has it that Mt. Tendong saved the Lepcha people during the great deluge which flooded the entire Mayel Lyang country, now known as Sikkim. The festival is an annual thanksgiving to the savior mountain.

Various literary and cultural programmes are held in the state capital to commemorate the occasion. On the concluding day, exhibits on traditional Lepcha food, costumes and ornaments are displayed.