Reaching new depths in Laos and the greatest river cave in the world

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 hidden depths for themselves…

7 mins

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.

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 scrambled 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.

Xe Bang Fai River Cage (Ryan DeBoodt)

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 and up to a staggering 120m high. It is considered one of the 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.

An 11-hour drive from Laos’ capital Vientiane, Xe Bang Fai is hidden in a remote area of thorny karstic peaks, deep in Khammouane Province. To the west lay the Annamite Mountains, buffering the border with Vietnam, and beyond those the mammoth Son Doong, now touted as the world’s largest cave and around four times more expensive to visit. But we had our own monster to conquer.

Keen to get started, we pumped up our inflatable kayaks on the banks of Xe Bang Fai River. Black butterflies alighted on the biscuit-hued sand around us, as we pushed out into a glittering teal-green lagoon. Around our heads, swallows swooped and glided through the cave mouth, the deafening squeaks of a million birds soundtracking our entrance to the cave.

Kayaking upstream, the light soon began to fail as we moved deeper, the soft plop of paddle on blackened waters sharpening in the darkness. Monstrous formations reared out of the torchlight, throwing curious shadows. The chamber was like a giant underground cathedral and almost reverently still, soaring karstic columns looming out of the dark as the last glimmer of outside light was extinguished.

 Kea Lewnalie (Claire Boobbyer)

After nearly two kilometres, the roar of water heralded the first of five rapids, blocking our progress and forcing us to portage the kayaks over the rocks. After breaching the first break of grey boulders, we returned to the water.

It was then that I spied the cave ceiling, bulging with folds like a silver Mr Whippy ice cream. The deeper we voyaged, the larger the boulders and pillars appeared to be – and the more impressive and grotesque their shadows.

Before long, a bank reared out from the dark and we made another pit stop, this time in search of a cave native: the world’s largest spider. The giant huntsman (or Heteropoda maxima) has a leg span that can reach a whopping 30cm and was first discovered in a cave in Laos in 2001.

Thinking it was like any other spider, I immediately set about looking for large glistening webs in my lamplight, only to be gently chided by my guide: “Claire, they don’t spin webs – these things have teeth!”

My blood drained cold at the thought, but I needn’t have worried. After a fruitless few minutes’ spider-hunting, we finally discovered something altogether less intimidating. Into our light scuttled a beautiful emerald-green beetle with a bronze belly, and then a huge bee-striped dragonfly, blown into the cavernous mouth of the river passage.

Paddling deeper into the cave, I admired its curves and folds, the walls undulating around us like curtains made of limestone. Then the roar of surging water sounded Claire again. It resembled the swirl of a giant drain, and with it came the sense that we might be swept away. But when the river calmed after crossing each set of rapids, the water became so still that it was hard to tell where the passage wall met the river line.

 Bang Fai River Cage (Ryan DeBoodt)

After nearly seven kilometres of kayaking, a faint light started to bleed into our horizon. We emerged into the jaws of the cave’s exit, a huge gouged door partially blocked by outsized boulders.

Beyond, we could see bouncy foliage with swallows zipping in and out. Phet, my other guide, gathered driftwood, lit a fire and warmed a lunch of sticky rice and beef strips stickered with sesame seeds. Before tucking in, he made an offering to the cave spirit to ensure our safe return.

On the way back through the cave, I trailed my lamp on the ceiling. Scrapes and dents were scratched across the limestone, leaving an impression of paw prints belonging to some ancient beast, while above us jagged stalactites formed the remnants of a natural portcullis.

We made good time and soon reached the entrance. Just as the light began to spill in, we parked our kayaks and climbed some steps to the ‘Dragon’s Hatchery’. Passing bulbous rock structures and cracked-earth fragments that resembled broken chocolate, we reached our goal.

Here, neatly laid out in rows, were enormous hexagonal ‘pearls’ – calcium-formed shapes smoothed to a gem-like sheen by dropping water. Some of the largest of their kind are found here, and they could easily have been the eggs of dinosaurs, crystallised over millennia.

 Hexagonal ‘pearls' (Claire Boobbyer)

Beyond the ‘hatchery’, the cave held one last surprise. Stepping out onto a naturally formed balcony, out over the water I could see a dangling, gnarled limestone claw dropped from the ceiling, seemingly ready to plunge and grab any exiting kayakers. No wonder there were tales of vengeful spirits, I pondered, as we left the darkness behind.

In the dying light of the afternoon, we set up camp on the beach. Phet made us a dinner of pork with ginger by the water’s edge, as swallows skimmed overhead. The stars were hanging high in the night sky when Mr Lewnalie arrived, having trekked the few kilometres from Nong Ping village. He pitched up with a heavy jar of rice whisky, which we eagerly sucked down through bamboo straws to ease in our approaching sleep.

I awoke to find white butterflies circling above the water as sunlight spread gently over the chiselled limestone outcrop that wrapped the lagoon. I was curious about what lay beyond this natural amphitheatre and its jagged battlements, so we broke camp to plunge further into Hin Nam No National Protected Area.

The park’s 820 sq km might seem an inhospitable land, but its limestone outcrops shelter a wealth of rare primates, from the black langur and red-shanked douc to the Annamese macaque.

Less than 50 years ago, though, it was less hospitable still. During the Vietnam War, the US bombed Laos incessantly to curtail north Vietnam’s communist forces from gaining further ‘red’ ground. Between 1964 and 1973, over two million tonnes of ordnance was dropped, earning Laos an unenviable record: the most bombed country on Earth.

As we drove out towards Sephan village, on the outskirts of the park, my eye was drawn first to the sharp limestone turrets and then to the ground. Peering closer at the roadside grass, I realised that on either side of the road were huge craters, and not just one or two. The area had clearly been pelted with bombs, leaving the landscape still bruised 40 years later.

 Campsite (Claire Boobbyer)

When we arrived, I spoke to some of the villagers as we sheltered from the hot sun.

One local said: “I never thought I’d see the village earth again, there were so many bombs. Even now, we have to be careful in our fields.”

Clearance of unexploded ordnance (UXO) is ongoing here and the Mines Advisory Group (MAG), a UK charity, has been working in Laos since 1994, clearing 202,793 UXOs.

As we wandered through the village, I noticed the villagers had their own approach to dealing with old shrapnel. Cluster bombs had been converted into troughs for feeding pigs and elongated boats. One man had even clad his entire house in scrap bomb metal and built an access ladder out of discarded bomb fragments.

Near to Sephan lies another cave called Tham Long, where we met guide Ky Doungluedee. Between 1966 and 1974, from the age of 9 until 18, he lived inside it alongside 19 other families, all sheltering there to escape the bombing. As Ky explained, even tradition was against them.

The villagers believed the cave was holy and that the spirit it contained might eat humans, so they had to sacrifice monkeys and buffalo in order to live there.

While exploring the narrow shaft inside the cave, and seeing the marks caused by lighting fires for cooking, I asked him how the shelling had sounded.

“The bombs were like constant lightning,” he explained. “They shook our bodies to the core.”

Then, no sooner had the words escaped his mouth a loud boom shook the ground. My blood ran cold and I felt a sensation in my upper gut, just as he had described.

“What the hell was that?” I exclaimed, as Ky calmly pulled out some tobacco rolled up in a leaf that he topped and tailed and started to smoke.

Thankfully, it was MAG working in the fields nearby, safely blowing up a UXO.

Next, Ky took us to nearby Tham Nam cave, a particularly popular spot for skittish dragonflies and where some of the Viet Cong (Vietnamese Communists) had sheltered during the war. But one day, during a dance show, a US bomb hit the roof and dislodged a huge rock at the entrance, meaning that we could only peer in from the edge to catch a glimpse of the dark auditorium-like space.

 Hin Nam No (David W Lloyd)

Ky had explained that there were more Viet Cong hideouts in the Hin Nam No, so we set out to find them the following morning from the remote Thongxam village. Crossing rice fields, walking past the Yoy minority spirit house, a small shrine to the local protecting spirit, and into a forest accompanied by periwinkle-hued butterflies and red dragonflies.

Bridging a series of small streams, we passed thickets of sandalwood, jackfruit, wild orange and cardamom as we tramped towards our destination: the 60m-long Nok Aen (or ‘Swallow Cave’).

Our guide, Kham Leuang, told us that it’s thought up to 3,000 Viet Cong once sheltered in Nok Aen. Walking through the boulder-strewn, pockmarked cave, accompanied by rippling flights of swallows, we found bowls, a tin and a shoe – although these were more likely recent additions.

Every year, I was told, the villagers trek here on the full moon in June to collect baby swallows for food – a local delicacy.

As we emerged from the hollow, I practised my spider-hunting technique and searched the cave’s crevices for a giant huntsmen until I finally found one – albeit lying dead in its resting place. Then, after fuelling up on a lunch of sticky rice, sausage and chicken at the mouth of the cave, we headed back through the forest for a chance to see some of the livelier residents of Hin Nam No.

 Preparing dinner (Claire Boobbyer)

Not far from Ban Thongxam lay Pha Koud, where ribbons of karstic fortress bulge out of the landscape. With local guide Tom, we moved off-road closer to the serrated ridge. There we waited, scanning the ridge with our binoculars. All of a sudden there was a lot of twitching in the trees, and at last we spied the local Annamite macaques, bouncing around on their giant spiky platform, eating and sun-bathing while the villagers below collected water and corralled their pigs and dogs.

It felt good to emerge from the darkness of the cave into the warm sun, to see how life continued in this once bomb-flogged land, and how its people now embraced new visitors, replacing memories of unwelcome guests who blighted their land more than 40 years ago. From exploring the region’s troubled past and unusual landscapes I learned one unmistakable truth: a cave is never simply a cave here. They represent shelter, history and tradition, and to understand all three better, you need to head underground.


The author travelled with Audley Travel, whose six-day tailor-made itinerary includes two nights in Thakhek, internal flights, kayaking and camping, one night’s homestay in Nong Ping and one night in Langkhang, plus visits to the UXO villages, trekking in Hin Nam No National Protected Area and all internal flights, transfers and guiding. A similar 16-day itinerary takes in Thakhek along with the highlights of Northern & Southern Laos.

See for details or to book. 

Main image: Xe Bang Fai River Cage (Ryan DeBoodt)

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