Although the Mekong river slides through six countries and various climates, its geographical and spiritual source is said to lie on the high, dry Tibetan plateau.
The spiritual source of the Mekong
The Mekong river - one of the world's longest - provides food, water and livelihoods to some 60 million people in six countries.
For much of its journey, it slides through tropical climates; places like Vietnam and Thailand that keep you swatting insects and sweating day and night.
But the exact source of the Mekong River has long been disputed.
Tibetans believe the spiritual source of what they call the "Dza Chu" (the river of rocks) springs from the near-mystical Zaxiqiwa Lakes on the high, dry Tibetan Plateau in a remote part of China's Qinghai province.
A long-running search
Tibetans know that the "real", geographic source of the Mekong lies further up on the glaciers of the high mountains that rise from the plateau.
For years, explorers have tried to determine exactly where that is.
At the turn of the 19th Century, French explorers claimed to have found it.
Another Frenchman - Michael Peissel - quite famously plotted a new spot in the mid-1990s, at a time when Japanese teams also worked hard to locate the source.
In 1999, Chinese teams determined the source to be higher, at Jifu Mountain.
The most recent report comes from explorers Pieter Neele and Luciano Lepre, who published their findings in 2014.
They described yet a new source: a stream from a glacier at 5,374m on an unnamed mountain beside Jifu.
But the spiritual source holds great significance for the Tibetan people.
Light on the high prairies
The 270km journey to the clear headwaters from the nearest airport - Yushu airport in Qinghai Province - rarely falls below 4,000m in elevation and climbs as high as 4,900m.
As we drove, every vista was an earthy palette of prairie, the highest mountains and the bluest skies.
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