Situated in the great loop of the Brahmaputra, one of the last places on earth to remain unexplored until the late twentieth century, the snowy peak of Namchak Barwa rises to 7,756 meters (25,439 feet). Here the majestic river, called the Tsangpo in Tibet, plunges between the mountains to emerge one hundred miles further on, 2,700 meters lower. It was not until 1998 that American explorers discovered the 'Hidden Falls' whose existence had long been suspected. 1990.