The Mekong River, at 4,180 kilometres the 10th longest river in the world. The Mekong has its source in the icy wastes of the eastern Tibetan plateau. It flows south and east, through China, Myanmar, Thailand, Laos, Cambodia and Vietnam, emptying into the South China Sea through a wide delta south of Ho Chi Minh City (Saigon).

The Mekong is of immense significance as a natural boundary. Its unpredictable waters and shifting bed make fording or bridging almost impossible. From the bottom of the river jagged rocks as sharp as teeth extend to and above the surface of the river, making navigation dangerous. Before you abandon ship, be reassured that your captain knows every rock in the river, and the Pak Ou boats have a hardened steel hull, so we can relax!

In ancient times, the Thai people fled across the Mekong from south China to establish the kingdom of Siam (now Thailand), over 700 years ago. Later, the river protected Siam from invasions from the east. The sometime kingdom of Laos, without this natural protection, fell under the control of various east Asian civilisations, such as the now ancient empires of Champa, Funan, and the Khmers of Cambodia, and later the Siamese (Thais) the Chinese and Vietnamese.

Later, in the colonial days of the French and British empires, the Mekong marked the western edge of the French empire of Indo-China; with Siam (Thailand) preserving its own independence as a buffer zone between the British, in Burma, and the French to the east.

This century, during the Vietnam War, the west bank of the Mekong provided bases for raids against the advance of the later triumphant communist armies in Laos. Following the war, anti-Communist forces escaped west across the Mekong to refugee camps in northern Thailand.