The river caves of Laos’ Khammouane Province have long provided shelter, food and solace to its native Laven people – now visitors can explore their history and depths for themselves …

the yawning gash in the rock face marked the gaping door of the cave, which was said to house a holy spirit no one would ever dare cross. The spirit protected the Laven minority people of central Laos, and there was a time when locals would never have risked entering the darkness beyond its illuminated hallway. Every year, they honoured it by sacrificing a cow or a buffalo, and as if proof were needed, none of their families had ever died while collecting the high-up swallows’ nests – to make bird’s nest soup – even when they fell.

In 1995, French cavers arrived with a map and told the Laven locals of nearby Nong Ping village that it was possible to pass through the cave and emerge at the opposite end, but the villagers, frozen with fear, refused to go. Instead, they rambled over the top of the ridge to meet them on the other side.

Then, in 2007, the Laos government, the tourist board and a German development organisation persuaded the then chief of the village, Kea Lewnalie, to enter the cave. He thought he would die, but when he emerged unscathed, the locals cried:

“What’s it like?” To which the sexagenarian chided: “It’s just a cave!” to peals of laughter from his 200- strong community.

But it isn’t just a cave. Through Xe Bang Fai River Cave flows 6.5 kilometres of navigable water, its walls ballooning to 200m wide in places an d up to a staggering 120m high. It is considered one ofthe world’s largest active river caves, yet has barely been heard of – even locally. In the previous dry season, just 224 travellers visited its depths, hidden beneath central Laos? Hin Nam No National Protected Area. But I was curious to see them for myself, and to explore a part of the country still dealing with the legacy of a war that ended over 40 years ago.