Mahalangur Himal is a section of the Himalayas in northeast Nepal and south-central Tibet extending east from the pass Nangpa La between Rolwaling Himal and Cho Oyu, to the Arun River. It includes Mount Everest, Lhotse, Makalu, and Cho Oyu — four of Earth's six highest peaks. On the Tibetan side it is drained by the Rongbuk and Kangshung Glaciers and on the Nepali side by Barun, Ngojumba and Khumbu Glaciers and others. All are tributaries to the Koshi River via Arun River on the north and east or Dudh Kosi on the south.