Singba Rhodendron Sanctury (Area - 43 sq. km and Alt 3048 - 4575 mts.) is located in North Sikkim in the famous Lachung Valley at a distance of 137 km. from Gangtok. The sanctuary is bounded on its southern periphery by the Yumthang Valley known for its alpine meadow and hot springs. It is hemmed in on the east by high rugged Chuba - Sagochen mountain ranges and on the west by part of Chomzomei Tso extending up to Lava pass. The picturesque Yumthang River flows through the sanctuary, which is known for its unique abundance of Rhododendron trees and shrubs, 40 species of which are recorded from Sikkim alone, that ablaze in color during March - May.
Rhododendron nevium-the state tree occurs through the sanctuary, which is also rich in ground flora such as primulas, potentillas, gentians, larch, juniper, maple with trailing lichens. They also abounds in silver fir, spruce, dense carpet of moss protecting the soil and its inhabitants from the chhu at Phunyi in 1978 and have been flourishing since. Lachung is the last frontier village before reaching the sanctuary. Facilities include Angling in Phuniya Chhu and Yumthang Chhu from April to Spetember.