A small settlement and a mountain hamlet, Tonglu is along the route to Sandakphu and falls under the Darjeeling district. Tonglu is actually one of the peaks of Singalila range and is situated at an altitude of 10, 130 ft. Previously this place was a part of Sikkim and was known as Mount Tonglu. This period was the time when Joseph Hooker came to this place and carried out many plant hunting expeditions in Darjeeling and Sikkim.