The Karnali is Nepal's longest and largest river and with its tributaries, it drains most of the Far west of Nepal the wild west. The area that it flows through is wild and relatively unpopulated with some of the most pristine jungle scenery in Nepal, and abundant wildlife. The rapids are also pretty wild, with the river building to its climax in these lower canyons. The valley narrows into a series of canyons, the river speeds up and there are big rapid, one leading into another, almost continuously down to the Seti River. The river winds through some magnificent un-spoilt scenery, eventually emerging onto the plains flowing through the Royal Bardia National Park to join the Ganges. The Karnali is more constrained by its canyon walls giving bigger more continuous and serious rapids. This constrained nature of the river means that any increase in volume has a more pronounced effect on the difficulty of the rapid and this makes it a river that is best run at low and medium flows in higher water the Karnali is a serious commitment.