 River Tsangpo (Tsangchu) which originates from Lake Manasarovar in Western Tibet flows through eastward when it reaches Mt Namcha Barwa, its bend making a U shape turn to penetrate into lower Himalayan ranges, thus carving one of the deepest Canyon in the world.Water dropping above 3,000 meters near Phe, about 300 metres at the end of the gorge.The river is called Tsangchu a famous river in Pemakoe, like kyichu in lhasa.