Author Rick Fuller: see full article here
The thick jungle canopy provides a welcome break from the sweltering Vietnamese sun, casting a verdant shade over our group of ten as we trek along the narrow, slippery trail. We’re as out-of-place in this environment as newborn fawns, blinking and staring around with wide eyes and flaring nostrils at the unfamiliar terrain and the musky scent of the dense foliage. The air is thick with humidity, causing perspiration to soak our clothes despite the dappled shade. The cacophony of cicadas fills the air, their relentlessly loud chirping serving as a rhythmic backdrop to our trek. As we descend along the narrow trail toward a river bottom, the temperature rises, enveloping us in a warm embrace. Limestone cliffs spring triumphantly and majestically from the lowlands, their jagged edges and crevices a testament to the relentless erosion of both water and time. These towering monoliths dominate the valley, creating a stark contrast against the vibrant greens of the surrounding vegetation which climbs their flanks. Swirling misty clouds born of the thick humidity lazily circle their tops, occasionally dipping down their flanks invoking Jurassic-era vibes to the remote jungle.
With only brief pauses, we navigate the uneven terrain, descending steeply, stepping carefully over exposed roots and jagged rocks that threaten to trip the unwary. The soft thud of our footsteps mingles with the burbling of the river below, creating a symphony of nature that seems to envelop us entirely. One of our group slips in the mud and lands painfully on her back. A safety assistant rushes to her and helps her up. She’s okay, but the safety assistant stays close, ready to catch her if the tread of her hiking shoes fails her again.
We are alone in the thick, steamy jungle of the Phong Nha – Ke Bang National Park in the north-central part of Vietnam, very close to the Laotian border. Access to the park is carefully controlled by the Vietnamese government, and though the roads through the park are open to traffic, strict laws prohibit anyone from leaving the roadside without being part of an official tour group, operated by only one company in Vietnam, Oxalis, and strictly limited as to number of persons, both per day and per season. As if to emphasize these laws, a park ranger catches our group and plods past us, his nimble feet well-accustomed to the hazardous trail. He carries a heavy backpack that contains bags of rice poking out the flap and a thick green vegetable like a cucumber on steroids strapped to the top. We are told that he is headed to his post where he will stay for a week, guarding the jungle access against unauthorized visitors.
As we press on, the cicadas get louder until their drone becomes almost piercing, and the jungle canopy begins to open up. The absence of any breeze only adds to the stifling atmosphere, and the sun’s rays begin to pierce through the sparse tops of the tall trees, casting a golden glow upon the land around us. We keep a wary eye out for snakes including several types of vipers, a cobra, and a constrictor that are all native to this area. The scent of decaying vegetation and damp earth fills our nostrils, a welcome change from the smell of burning garbage and plastic that permeates the cities we transited on our way here. There’s a certain magic to this place; this humid jungle gives a sense of adventure and discovery that fuels our determination to press on and uncover its secrets.
After about 45 minutes of descending, we finally reach the river bottom, and our tour guide lead, Tha Tran, steps into the knee-deep water. The river is not wide, and rocks provide a platform upon which to leap and avoid getting our feet wet, but Tha, with a mischievous grin on his face, uses his staff to splash the rocks, turning them from dry and easily navigable steps into slippery instruments of chaos. Its time to get our feet wet, and Tha makes it clear that there is no avoiding the wading of the rivers that will become part of our very existence for the next four days.
The ten of us, strangers until the previous evening, are gathered together here in this remote national park of Vietnam for one purpose: to explore Hang Son Doong, the largest cave in the world. This behemoth cave, created by eons of rushing water through the vast permeable limestone cliffs that inundate the landscape of this country, was only officially discovered in 2009 by members of the British Cave Research Association. Prior to the discovery of Hang Son Doong, the largest known cave in the world was Deer Cave in Malaysia. Deer Cave enjoyed this prestigious title from its survey in 1985 until the completion of the survey of Hang Son Doong in 2010 which would reveal a volume more than twice that of Deer Cave. An absolute monstrosity that lay unseen by human eyes for eons, its secrets waiting patiently to be mapped, and we were all giddy to be some of the very few who have had the pleasure of bearing witness to its glory.
The full story of the discovery of Hang Son Doong (Hang means “cave” in Vietnamese, so this is the Son Doong Cave) began in either 1990 or 1991—the literature is unclear, along with, perhaps the memory. In the rainy season of one of those years, Mr. Ho Khanh, a local villager who relied on illegal logging to support his family, was searching the jungle for aloe wood, also called agarwood, a very precious, very valuable, and very difficult to find wood which exists sparsely in the deep jungle. Here again, the story varies, as some, including our tour guide, Tha, tell us that Ho Khanh was actually searching for the Sua tree, an even more rare tree than agarwood, and one that is prized by the Chinese and that can sell for up to $1000 per kilo. Whichever account is accurate, what seems true is that Khanh was searching for a rare tree, and perhaps he was looking for either of these rare and valuable woods, something that seems quite plausible for an opportunistic and knowledgeable logger who risked illegally scouring the dense National Park junglescape in an effort to support his family.
Initially with two compatriots, Ho Khanh separated from the others and trekked through a massive cave called Hang En, following the river that flows through it, the easiest path through the dense jungle. After Hang En, the river disappears underground, and Khanh climbed above the valley, his eyes scouring the jungle for the elusive tree. Rainstorms appeared and began dumping on him, and his eyes noticed mist swirling and streaming from the side of a limestone cliff, a sure sign of a cave entrance. He worked his way over to the entrance, a cave he had never before seen nor heard of, and hunkered down just inside and out of the downpour. When the rain finally ceased, Khanh returned home and promptly forgot about his discovery. Caves are generally meaningless to the local people as with few exceptions, they provide nothing of value. This one in particular was of no value as the entrance was narrow and the cave descended steeply into a yawning maw of blackness where a cold wind rose from the inky, stygian depths, meeting the warmer and humid air of the jungle to create the mist that Khanh observed. That deep blackness and the accompanying roar of a great river in its mysterious depths held only nightmares and prehistoric limbic fear for the young man who wanted nothing to do with whatever monsters waited below.
Fast forward to 2007 when Howard Limbert of the British Cave Research Association fortuitously met Ho Khanh. A prodigious searcher of caves and a world-renowned caver with decades of experience, Limbert’s group had discovered and mapped hundreds of caves in the limestone cliffs of the Vietnam jungle over the previous decade. Ho Khanh had been engaged by the British caving team for the previous season to help them discover new caves, and his expert guidance had been fruitful with dozens of cave discoveries during his tenure. In 2007, the British crew enlisted Khanh’s help once more, and at the end of that season, Khanh met Howard. In their talks, Howard told Khanh that he was specifically looking for a cave that would connect the massive Hang En with another cave known as Hang Thoong. The river that flowed through both caves disappeared underground at some point in the impenetrable jungle, and Howard Limbert suspected there must be another cave hidden in that area. This description triggered the memory of the rainy night almost two decades past that Khanh had spent bunkered in the entrance of an unknown cave in that very area, a cave that spewed cold air from unfathomably stygian depths with swirling mist revealing its existence in the dense canopy, and Khanh led the group out in search of this cave he vaguely remembered. Their search was unfruitful, and the team returned to England at the conclusion of the season. The following season, in 2008, Khanh, wanting to impress the group he admired and that probably compensated him well, went out on his own, searching for the cave of his distant memory. This time, he found the entrance and marked it in his mind. The vast depths were too steep and dangerous for him to explore on his own, but he returned to his village to await the return of the Caving Expedition. When they returned in 2009, Khanh excitedly led them to the entrance. He was worried that this cave might be a dry cave with no special significance, its depths merely imagined, the subterranean river for which they searched located elsewhere. His worries were for naught though, as the British Cave Research Association stepped up to the tiny hidden entrance, unaware that they were on the brink of the greatest and most exciting discovery in their history, and arguably in all the history of caving expedition.
In 2024, the new cave, named Hang Son Doong, or “Cave of the Mountain River” has become a carefully regulated tourist attraction, bringing cave afficionados from around the world who pay $3000 each for the privilege of being one of the lucky few to explore its depths. Joining Tracy and I on this adventure are eight others, the maximum tour allowable size, and we have all booked this tour at least a year in advance, so great is the demand for the limited number of annual slots. Shockingly, our group is composed entirely of Americans, though the majority are of Vietnamese descent, returning to the land of their parents to bear witness to one of the world’s greatest discoveries. Two friends, middle-aged wanderers and explorers Kay and Phuong have traveled from Orange County, California. Kay owns a successful travel and tour company that focuses on Southeast Asia packages and tours. Phuong is Kay’s lifelong friend, and she spent months preparing for the rigorous hiking and climbing we’ll encounter on this tour by hiking all over southern California. Along with Kay, Phuong is very involved with a charity called Hope for Tomorrow which provides much needed medical and dental support to the numerous struggling communities of Southeast Asia, a worthwhile and magnanimous endeavor.
Two sisters, Truc and Ly have traveled from Houston and Tampa Bay respectively. Joined by their boyfriends, Anthony and Justin they are the youngest of the group, in their twenties and thirties. Truc is an accomplished orchestra musician and violinist who was born in Vietnam but emigrated to America to study music. She was also once a contestant on a reality show, making her the celebrity of the group. She’s an adjunct professor at San Jacinto College teaching violin, quite an accomplishment for someone of her youth. Her older sister, Ly spearheaded their involvement on this tour, convincing Truc to join her on this once-in-a-lifetime expedition. Originally from Ho Chi Minh city, Ly moved to the United States in 2001 and works as a General Medical Technologist. She has the ambitious goal of visiting every American National Park, a goal that apparently was deferred by the importance of this trek in her native country. Anthony and Justin were friendly and bright, completely devoted to the security and comfort of their girlfriends while I often wasn’t sure if Tracy was still on the trail or had turned back. Justin is an engineer who was born in Hong Kong but grew up in Canada. He studied chemical physics and medical biophysics and works as a designer of MRI scanners. Along with elevating the collective IQ of our group, his other role was to carry a larger-than-normal backpack for most of the trip that contained not just his own gear, but also all of Ly’s belongings. Anthony, a commercial pilot who studied Geology at USF was fortuitous enough to be friends with Justin when Ly set up this trip. I say fortuitous, because two’s company and three’s a crowd, and when Ly invited both Justin and Truc to join her on this expedition, they needed a fourth, and with a flourish that would make a magician proud, Anthony appeared. When I talk about the formidable nature of this trek, I’m not exaggerating, and Anthony would find himself sick on day two, which could have spelled disaster on such an arduous endeavor. Although he had to rest on a couple of occasions while coughing up mouthfuls of gunk, never once did he complain or slow down the group. He accomplished this trek while sick and coughing and still managing to help Truc along and tend to her needs, and while that devotion may have made me slightly nauseous, I found myself in awe of his strength and fortitude.
Rounding out our ten are Damien, a Vietnamese-American finance specialist with a global oil and gas company from Houston and Jeremy, the elder of our group at the age of 65. Damien and Jeremy are polar opposites, Damien flashy, splashy, and swashbuckling, a jester who had us all in stiches on numerous occasions with his hilarious stories, while Jeremy is much more reserved, stoic, and conservative, an intellectual who spends his mornings engaged in meditation and yoga while the rest of us are still stumbling around looking for coffee. Jeremy is a dual-citizen American-Canadian Jewish expat currently living in Melbourne, Australia. The business success and intelligence of each member of this group is amazing, making me by far the least successful of the group, an inferior tagalong and an outsider, though this probably should be no surprise as the cost of this tour is a steep barrier to entry, drawing only those with a good amount of disposable income. Or significant others with such. Ahem.
As disparate and diverse as this group is, we comfortably and casually chat and get to know each other as we journey along. We met for the first time at the mandatory safety briefing the previous night, where our shoes and backpacks were inspected by Tha and by our safety specialist, Hieu Ho, a local man who has worked extensively with the British Cave Research Association, and who has spent a remarkable two full years of his young life inside Son Doong Cave, with more than 150 unique trips into its depths. This briefing occurred at Oxalis headquarters in Phong Nha, a small town that has prospered with the plethora of tourism brought into the region by Son Doong and the many other magnificent caves that dot the national park.
The first river crossing complete, we rest a bit to dip our heads in the refreshing water and sip from our bottles to replace some of what we’ve lost in sweat. As we lounge, two trekkers pass us going back the other way. They are in the jungle illegally and they’ve been caught by the ranger who passed us earlier. He has sent them back out of the jungle and Tha tells us that they’re lucky they haven’t been arrested. Our break over, we sling our packs onto our sweaty backs and along with Tha, Hieu, and the six capable safety assistants who accompany us, we continue our venture deep into the heart of the Vietnamese jungle. Despite the weight of their heavy packs, loaded with safety equipment and emergency supplies like a satellite phone and several well-stocked first-aid kits, our guides navigate the terrain with effortless grace, their movements fluid and purposeful. Unlike the trekking boots and heavy-tread trail runners worn by our group, our guides (as well as the porters and chefs) all wear thin sandals, albeit sandals with a heavy tread. The sandals dry out overnight, and with new socks every day, keep their feet from acquiring jungle rot from repeated trekking tours. Our feet will be fine being wet for four days straight, but with shoes like ours, their feet would be wet perpetually.
We continue on through the flatlands of the river valley, crossing and recrossing the river numerous times, a task we begin to find refreshing as the water cools our overheated feet each time. Tha takes the time to stop and teach us all about the flora of the Vietnamese jungle, paying particular attention to pointing out what he calls, “itchy plant,” officially Nang Hai, a devil’s club or poison ivy-type plant that is prodigious throughout the terrain. This plant looks innocuous and innocent, tough to discern from the similar foliage that surrounds it, and Tha and the other safety guides are quick to point it out when it intrudes on our path, the call of “itchy plant!” ringing out every few minutes. As terrified of this plant as the guides, who aren’t scared of anything we’ve yet seen, are, we all give it a very cautious, wide berth.
After a bit more trekking through the wide-open spaces, our bodies no longer protected by the jungle cover, we arrive at a remote village home to an ethnic minority Vietnamese community. The village is called Bru Van Kieu, and their simple dwellings and way of life stand in stark contrast to the world we’ve left behind, a testament to their isolation and self-sufficiency. At least this seems the case, until we encounter a device that looks suspiciously like a cell-phone tower. Tha confirms that this is what it is, however, the tower is solar powered and does not connect to any tower to the outside world, serving only to allow communication between the small villages that dot the bottomlands of the verdant valleys. 52 live in this community, and they are shy and reclusive. We get a few waves and shouted “hellos” from some children, and some curious stares from a couple adults, but we otherwise see nobody. In the heat of the day, the village seems to have embraced a languid pace, its inhabitants seeking respite from the oppressive sun. A quiet hush has fallen over the settlement, broken only by the occasional murmur of muted conversation, or the light, playful laughter of the few children. The few adults we do see glance our way and nod or raise a hand, their weathered faces etched with the stories of a lifetime spent in harmony with this remote and rugged land. We cross their cattle fences using small built-in ladders. Dogs languish in the shade, giving us barely a glance as we pass, and cattle and chickens likewise ignore us to go about their busy lives with no regard for our group of interlopers.
We stop at the home of the local chieftain where a lunch spread is laid out for us in the shade of his home. We see no sign of him, but the two chefs assigned to our group have spread out delicious fare, and a lot of it. We remove wet shoes and socks and lay them out in the sun for drying, a futile effort in the humidity. Camp shoes, a must for this trek, are donned, and we sit for a delicious lunch of rice paper wraps, hoagie rolls, meats, veggies, and large bowls of various Vietnamese noodle soups. Fruits, yoghurt, and cookies round out the dessert portion. Everything is delicious and there is plenty of everything except for the packages of Happy Cow cheese which Tha guards ferociously against my hungrily snatching paws, insisting that there is only one for each person. I play along like a good tour member eager for group harmony. For now.
Bellies full and spirits renewed, we don our wet shoes and bid farewell to the lethargic village, continuing our journey, winding our way through the lush, verdant valley. The wide expanse of the river basin stretches out before us, its meandering course beckoning us forward as we cross and recross the snaking channel numerous times. One of our eagle-eyed safety assistants, his vision honed by countless expeditions, suddenly motions for us to pause. With a deft gesture, he points toward a distant tree high atop one of the jungle-covered limestone ridges where a monkey perches, its form almost camouflaged by the branches of the tree in which it rests. We marvel at the creature as Tha borrows Damien’s cell phone, an Android with a 100x zoom camera. The monkey, a long-tailed lemur, comes into sharp contrast in the cell phone camera and we watch with joy as it swings its way out of the highest tree branches and out of sight.
Onward we press, our path continuing to follow the serpentine river that carves its way through the valley floor. As we round a corner, our eyes, guided by the pointing finger of Tha, are drawn to a sight that leaves us awestruck. In the distance, camouflaged and partially hidden by the jungle foliage is a limestone cliff and the top edge of a gaping maw, a massive cave looming in the cliff side. Tendrils of mist curl lazily from the cavernous entrance, adding an air of mystery to the already imposing spectacle.
“Hang En,” Tha announces, his voice tinged with reverence for this ancient geological wonder. Although he’s seen this view hundreds of times, it is apparent that he understands the importance and magnificence of this site to our group. He also embodies a sense of pride in the wonder of these marvels that draw tourists from around the world to his small, battle-weary country.
It takes an hour to close the distance, and as we draw closer, the sheer magnitude of this cave becomes increasingly apparent, its towering entrance arch dwarfing us with its immensity. We work our way along the river which flows out of this cave. We won’t be entering Hang En via the immense arch, but rather through a small entrance carved by the river with which we’ve become intimately familiar. We step into the shaded darkness, take numerous photos, and then don our caving helmets and caving lights which strap to the top of the helmets. With a sense of eager anticipation, we activate the headlamps, their beams cutting through the encroaching darkness. Leaving behind the vibrant jungle and its now familiar sounds, Tha leads us as we take our first steps into the inky blackness that lies beyond. The silence is eerie, punctuated only by the muted roar of the river and the sound of water dripping from the cavernous ceiling above our heads. We cross the swiftly flowing river holding onto a rope to avoid any slip and falls. A few steps further and we encounter a massive rock fall, boulders the size of cars that have fallen from the ceiling over eons. Tha leads us up a path, cautioning us in the slippery parts as we trek across the dominating rockfall. We are working our way upward toward the massive entrance that was our first view of this cave, and as we cross under an overhanging lip of rock, we crest one of the plateaus of the rockfall where a magnificent view meets our eager eyes. Our first camp for the night, sprawled under the dome of the largest cavern any of us have ever seen.
Hang En is where we’ll spend our first night, and the camp has been already laid out for us via the efforts of the porter team that accompanies our group. 17 local Vietnamese men comprise the porter group, and if there are harder working, stronger and more capable men in the caving world, I would be shocked. These 17 men have carried a full complement of equipment and gear for our expedition, and they have beat us to the cave to have it set up for us when we arrive. I’ll talk more about this later.
For now, we are perched like mountain goats on a house-sized rock far above our camp, and we look down at it in awe at the sheer magnificence of the scene below us. Cameras emerge, and we take time posing for photos. The river we’ve crossed deepens and widens below us, and a raft awaits to take our group across to the campsite which sits on a flat, sandy beach in the gloom of the cave. Light from the massive entrance is muted but bright enough for us to move about without fear of tripping or falling. Tha and Hieu lead us carefully down the sprawling rockfall and to the raft where we board and are pulled across the 50-foot gap via a rope that spans the length. On the shore, we find our tents and drop our packs. Our porters have carried half of our personal gear in provided dry bags, and we find our dry bags to gather our belongings, remove our wet gear, and don comfortable, dry clothes. Some of us choose to go for a swim instead, and I’m one of them, putting on swim trunks and grabbing a required life jacket to head back to the water. A signal is given to the safety assistants, and one of them brings a chair to the beach to act as lifeguard. The water is cool and refreshing, drawing a gasp initially as I dive in, but then warming appreciably in feel. I scrub the sweat from my body and then toss the offensive lifejacket back to shore as I commit to staying within the 15-foot limit from shore to go without. Tha joins, along with a few of the group, and as we stand there chatting excitedly, fish begin to nibble at my feet. A “fish foot spa,” Tha calls it, and I let the fish enjoy their feast of my objectively nasty, pruned and peeling feet. Surprisingly, nobody else is getting a nibble while I’m being swarmed by no less than eight hungry mouths, and I make a joke that these fish rarely get to enjoy white meat. The reality is that my feet are probably just more disgusting—and thus yummy to fish—than most.
After the swim, we change into dry clothes and then sit around a charcoal fire as the light begins to fade over the cave entrance. Birds swarm above us, mistaken for bats at first until Tha corrects us. They are Swiftlets, and there are thousands of them. They nest in the ceiling of the cave, hundreds of meters above us in the gloom. Tha shines his intense flashlight up to the wall and points out what looks like sticks jammed into the rough-hewn walls. He informs us that this is rattan, a vine that grows in the forest and that he pointed out to us a few times along the trek. We’ve all heard of rattan furniture, a highly desirable and high-priced, rugged export from the area. As we struggle to understand how the jungle vine came to be lodged into the rock walls of Hang En, Tha ends the suspense and tells us that prior to Hang En being a tourist destination, for centuries, the local villagers have scaled the walls of this cave to reach the Swiftlet nests in the ceiling, seeking the baby Swiftlets which are a delicacy to the tribes. Our mouths drop in disbelief as we try to fathom villagers climbing these walls with no safety equipment, jamming rattan sticks into cracks for handholds, hanging upside down hundreds of meters above the cave floor, and tossing baby birds down to their deaths for some delicious soup. I wonder at how many human deaths must have occurred alongside the Swiftlet deaths right in this spot from a slip by a young climber over the many centuries of this practice…
Dinner is ready at 6pm sharp, as darkness is descending on the campsite. Lights are produced, and we gather hungrily at the table as our bountiful fare is laid before us. Chicken, beef, and lamb, stir-fried vegetables and rice, both steamed and fried. Various soups, wok-fried eggplant, and eggrolls. Our eyes are wide as we pile the food into the small cups used by locals for every meal. We gorge ourselves by repeatedly refilling the cups, but put hardly a dent into the lavish bounty spread before us. Tha ensures us that the porters eagerly await our leftovers, so we don’t feel bad about wasting any food. Although they’ve already eaten their own dinner, the calorie-burn of the work they put in leads them to a ravenous hunger that is satiated by our untouched leftovers as a midnight snack.
After dinner and some light conversation over the charcoal fire, full darkness descends, and I can hardly keep my eyes open. I’m ready for bed at 7pm but hold out until 8:00, thinking that must be the earliest acceptable time to slink away without disgrace. I’m not the first to disappear though, many in our group still suffering the effects of jetlag from the 12-to-15-hour time difference from the U.S. and exhausted by the arduous hiking we endured. Tomorrow will be even tougher as we’ll transit through Hang En, following the route of Ho Khanh from a quarter-century earlier. We’ll make our way to the hidden entrance to Son Doong and tomorrow night we’ll sleep inside that magnificent cave. Although I am filled with trepidation and anticipation for the next day, I’m sound asleep by 8:05pm, mere minutes after laying my head on the pillow.