The Khone Falls and Pha Pheng Falls (Lao: ນ້ຳຕົກຕາດຄອນພະເພັງ) is a waterfall located in Champasak Province on the Mekong River in southern Laos, near the border with Cambodia (Khmer called "Labak Koun"). The Khone Falls are the largest in southeast Asia and they are the main reason that the Mekong is not fully navigable into China.