Bardia National Park is the largest and most undisturbed protected area in the Terai region of the Nepal Himalayas, covering on the southern slopes of the Sivalik Hills. It is bordered in the south by the Babai River, and to the west by the Girwa River, a tributary of the Karnali. At Chisapani Gorge, the swift-flowing Karnali River emerges from the Shiwalik Range onto the broad plain and flows purposefully through the semi-tropical jungle. The park is famous for two Asian elephant herds, several deer species, gaur, nilgai, Himalayan tahr, serow and goral. The Karnali supports the endangered mugger crocodile, the gharial, a few remaining South Asian river dolphins and the golden mahseer.