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.
The Khone Falls are the largest in southeast Asia and they are the main reason that the Mekong is not fully navigable into China. The falls are characterised by thousands of islands and countless waterways, giving the area its name Si Phan Don or 'The 4,000 islands'.
The highest falls reach to 21 metres (69 ft); the succession of rapids stretch 9.7 km (6.0 mi) of the river's length. The average discharge of the cataract is nearly 11,000 m3/s (390,000 cu ft/s), though the highest volume on record was reached at over 49,000 m3/s (1,700,000 cu ft/s).
This prodigious expression of nature makes it a must visit southern Laos, and places have been built to take advantage of this great show..