mainly three major river drains Nepal - Kosi, Gandaki and Karnali are their tributaries. These are all perennial rivers forging through varied ranges running in an east-west direction. Other separate rivers originating from the Mahabharat Ranges include the Mechi, Kankai, Kamala, Bagmati, Tinau, Rapti, Babai and Mahakali. The first and last mentioned rivers act as international boundaries between Nepal and India. Then there are several lakes located mainly in the Himalayan Zone. Rara, Phoksundo, Phewa, Tilicho, etc. are the most popularly known large lakes of Nepal. Finally, glaciers of varied dimensions exist in the Himalayan region; Khumbu, Langtang, Kanchanjunga; Yalung, Ramtang, Barun, etc are the major glaciers of Nepal.