Royal Manas National Park covers 1,057 square kilometres of subtropical and temperate forest sweeping up from the Brahmaputra lowlands into the Himalayan foothills, and is one of the most biologically important protected areas in Asia. Tigers, Asian elephants, clouded leopards, gaur, water buffaloes, and golden langurs — found only in southern Bhutan and adjacent Assam — all live here. The park lists over 360 bird species, including several globally threatened ones.
Access from Gelephu requires a permit arranged through a licensed Bhutanese tour operator, and most visits are conducted as organised tours. The park is most easily entered from Manas town, southwest of Gelephu; the journey from town takes a couple of hours. Leeches are a fact of life on jungle walks in the monsoon season (June–September). The best wildlife viewing is in the cooler months from October to March. This is proper wilderness — infrastructure is minimal and the experience is all the more rewarding for it.