Khone Phapheng Falls

The Khone Falls are the largest in southeast Asia, and 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), with the highest flow on record at over 49,000 m³/s (1,700,000 cu ft/s).

Navigable efforts

Because the Khone Falls stop the Mekong river from carrying boat traffic to and from China, French colonialists in the late 19th century made repeated attempts to navigate the falls. Their efforts failed, which led to the construction of the Don Det–Don Khon railway on Don Det and Don Khon islands.