(This is part two of a multi-part article. View part one here: https://shorturl.at/iqQT1)
The echoing din of thousands of nesting swiftlets reverberates through the vast cavern, their frenzied chirping mingling with the soft, diffused light of dawn trickling in through the cave’s arching aperture to act as a reveille, calling us from our tents at 6am. Our jetlag lingers despite having already been in-country for five days, and we are bleary-eyed and in dire need of coffee. Despite our extreme fatigue the night before, sound sleep lasted for only five or six hours before a restless dozing took over the remainder of the night. Regardless, the swiftlets and the yawning maw of the colossal cave provide a surge of adrenaline as we’re reminded where we are and just what’s in store for us today. After more than a year of planning and yearning, today we will finally arrive at the legendary Hang Son Doong and bear witness to its grandeur.
With the dawn’s first light slipping through the cavern’s towering entrance, the crew is already a flurry of activity. Porters deftly pack away tents while the two camp chefs, Tu and Luan, have their kitchen humming, aromas of breakfast wafting through the cool air. Two safety assistants tend a pot of boiling water, carefully preparing pour-over coffee and steaming mugs of tea. We meander over and grab a mug of our preferred brews before settling around the crackling charcoal fire.
Sipping our beverages, we watch in awe as thousands of swiftlets dart frenetically in and out of the murky darkness high overhead. The cave is humming with their activity and I use my hand to cover my mug for fear of some unwanted creamer dropping into my coffee. From this very spot, in 2015, Good Morning America made a live evening broadcast to millions of waking American viewers, showing drone footage of Son Doong while the host recounted her trek, and the incredible effort to bring the mountain of equipment required to execute a live broadcast has since paid off well for both Oxalis and the Vietnamese locals who now rely heavily on tourism for their livelihood.
Tha and Hieu join us, energetic and friendly, brimming with barely withheld energy despite the early hour. Tha recounts tales of his early life as well as of the more than fifty treks he’s led through the legendary Son Doong cave.
Coincidentally, Tha was born in 1990 – the very year Ho Khanh first discovered Son Doong’s hidden entrance. As a child growing up in a poor village, he often spent his days searching for ordinance from the war, both unexploded and the exploded shrapnel, which he would play with for hours before turning over to adults to sell for scrap metal. Fortunate to attend university, he studied English and geology before intense guide training that led to a government guide certification. After working as an Oxalis assistant guide for five years, immersing himself in every aspect of the operation and learning the skills needed to flawlessly execute a trip as complex as this, Tha underwent specialized caving instruction from British experts. A probationary year followed, each tour meticulously critiqued by seasoned guides, until he finally earned certification to lead the extraordinary adventures upon which we are now embarked.
All 26 members of the guide team answer to Tha, though he only rarely has to intervene or give direction. Each of them is completely competent and knows their job very well, and Tha is free to spend most of his time with us, the clients, eating meals with us and hanging around the fire to tell stories and answer our questions. Telling tales of floods that have halted tours, Tha focuses his bright flashlight up to a point far above the cave floor on the wall. There, nestled well over 200 feet up in a crack in the limestone is a red bucket, and he tells us that flood waters reached that high a few years back, jamming the bucket into a crack where it remains unretrieved. Imagining the mild-mannered creek that flows lackadaisically below us as the raging monstrosity it would have required to toss that bucket to that height is almost impossible, but the mere presence of the bucket in that crack lends truth to the far-fetched tale.
At 0730 exactly, breakfast is served. Another cornucopia of choices awaits, and we stuff our faces with eggs, bacon, soups, breads, rice dishes, and various fruits weighted toward mango and dragon fruit. At 0900 we don our helmets and cave lights, slip back into our boots which, overnight, have miraculously managed to not lose even a gram of yesterday’s accumulated water, and climb the rockfall behind us to a point high above camp where we gather to take in the magnificent views and pose for pictures.
Dropping back down to camp, we slip into our packs and head out just ahead of the team of porters who fall in behind us. After marching across a sandy swale and crossing the knee-deep creek, we climb out of sight of the entrance light and into the reach of beams of sunlight from the exit. The trail branches and we continue to climb while the porter team with their gargantuan packs take the lower trail. We cross through a boulder field of car-sized rocks and past some towering, flowing calcite formations, beautiful in their unique intricacies. At the top of a rockfall, a splendid view of the exit of Hang En opens in front of us. The arching maw of the cave exit reaches hundreds of feet above the burbling creek, and as we sit to languish in the views, the porter team pops out below us, a well-rehearsed and flawlessly executed maneuver that allows us to fully appreciate the scale of what we’re seeing. Without the humans marching out of this magnificent cave while we perch on the rockfall high above them, the magnitude of the arch would be vastly underappreciated, and Oxalis has timed everything to perfection.
After marveling at the breathtaking views from our lofty perch, we reluctantly climb down to rejoin the creek below, wading once more through its cool shallows. Exiting the cave’s sheltering embrace, we find ourselves once again immersed in the verdant, steamy jungle that so enthralled us the previous day. We’ve crossed under the mountain that stands between the remote village and the entrance to Son Doong, and the river that carved this magnificent passage is but a shade of that which it is capable during the monsoon seasons.
Our path now follows this meandering and lazy river, at times trekking along its banks, at others wading directly through the waters that range from knee to waist deep. Towering limestone cliffs surround us on all sides, their craggy tops disappearing into swirling mists high above while the merciless Vietnamese sun is kept temporarily at bay by the shrouds of precipitation. Tha regales us with tales of leading tours during the sweltering summer months when temperatures often soar past 100 degrees Fahrenheit. The thought sends a shudder through me as I tip my hat into the creek, letting the refreshing waters cool my head, providing temporary respite from the already balmy low 80s heat. The lush jungle closes in around us as we press forward, while the ever-present humidity amplifies the sweat that trickles down our brows. There is a wild, primordial beauty to this rugged landscape that rejuvenates us, and we can feel the call of Hang Son Doong, its dark and mysterious entry passages awaiting our arrival.
After an hour of trekking along the river, it bends around a corner and disappears from site, a muted roar that seems to reverberate through the surrounding rock letting us know that it has not formed a placid lake, but is instead taking a tumultuous tumble underground. Logs and rocks present an impenetrable barrier, and beyond them, a towering limestone cliff bars our passage. Tha now warns us that we are about to ascend the steep slopes to our right, and that this is the spot where we’ll most likely encounter leeches. As we pause to drink water and prepare for the arduous ascent up the side of the mountain, a scream rings out. The safety assistants all turn and rush to the source which is coming from Ly who is grasping at her side in a blind panic. Fears that she has encountered a deadly snake are dashed as she manages to choke out, “leech!” as she makes repeated plucking motions at her side. Despite the advice that an encounter with an attached leech should be dealt with by simply spraying it with bug spray, an act that kills it almost immediately, Ly is panicked, and successful in plucking it off her skin which now bleeds freely. Tha sprays a disinfectant on her, wipes away the blood, and applies a bandage while one of the safety assistants finds the offending creature and crushes it.
The leeches here are generally very tiny, and we are told that they carry no disease risk, so their presence is much more of an annoyance than anything of which to be fearful. This encounter in the river bottom would be only the first of many in the next hour of hiking.
We ascend a narrow and rugged path up the side of the cliff, working our way both upward and forward as the thick jungle closes around us. The path is muddy, and leeches are legion. Awakened from their slumber by the footfalls ahead of us, they are attracted to the warmth of our passing feet, grasping on and moving upward like Slinkys in their desperate search for flesh.
At this point, I should note that the suggestion for this tour was long socks and long pants that could be worn tucked into the socks. I had never planned to wear long pants, bringing only one pair with me almost as an afterthought, and planning instead to wear shorts most of the time. At the safety briefing on the first night, I was surprised to learn that long pants were not a mere suggestion as I’d thought, but were in fact compulsory for all of the hiking time, only optional while in camp. Unfortunately, I’m considered huge in this culture, and Oxalis, while having a vast selection of long pants for purchase, could only find one pair in my size. Since I’d planned to wear shorts most of the time, I had also failed to bring long socks, which meant that even though I now had long pants, I could only barely stretch my socks up far enough to tuck the fringes of the pants into them. This left me quite vulnerable to leeches as my socks, made of cotton and stretched upward, left them permeable to the slippery, slimy, probing leeches which are capable (as it turns out) of slithering through the gaps in the stretched cotton.
Now, with each step, I envisioned the slithering pests probing the thin fabric, seeking any minuscule passage to my vulnerable flesh. Looking down when I could, I plucked two of the beasts off my shoes as they were tumbling their way upward. I could feel an itchiness on my ankle, and then another on my foot, a sure sign that the parasitic stowaways had gained access, but I refused to slow down the group, ignoring them and marching on.
After an effortful climb crossing sharp rocks on steep, muddy paths, we reach a shelf where the jungle opens up. Ahead we can see a plastic barrier which we are told is a snake barrier surrounding a lunchtime camp. Bathrooms and a cooking station are set up, and we all drop our packs and perform a leech check. I do indeed find leeches attached at the points where I’d felt the itchiness, as well as two other spots where they have bitten, one of the leeches still curled up in my sock. With the ones I’d plucked off my boots before they could make it to the promised land, this makes seven leeches in total that have been on my person. Nobody else in the group has any attached to them, and only one or two have been plucked off their clothing during the climb. Once again, it seems that the Vietnamese critters are enthralled by the rare presence of white meat in their midst. Or, once again, perhaps my feet are so disgusting that they continuously draw a stampede of hungry parasites.
Lunch is magnificent and filling once again, and Tha points from our camp outward into the valley where the mist is moving and curling. “The entrance to Son Doong,” he says. The same flowing mist that drew Ho Khanh to recognize a cave and a spot where he could shelter from the storms now beckons us, the eerie pale tentacles that blow outward and then curl back under seeming almost like fingers motioning us to its dark depths. We’re excited to finally be here and we don our soaked shoes, shoulder our packs, and follow Tha along the jungle path to our destiny.
When I first heard about Son Doong, it was hard for me to fathom how a cave of this size could exist without ever being discovered until 2009, or more accurately, only being discovered once before 2009. Surely some primitive local knew about this cave before now? Surely ancient hunters had stumbled upon it at some point? Well, perhaps that is true. However, laying eyes on the actual location of this cave makes it very easy to believe it had indeed never been seen prior to 1990. The jungle is dense, and other than the well-worn path we trod, laid down only for the purpose of tourism, there would be absolutely no plausible reason for anybody to have ever climbed to this point and fought through the thick jungle in order to stumble on this cave entrance. Were it not for the relatively recent desire of the Chinese for the rare trees that grow deep in the heart of the Vietnamese jungle, it is easy to believe that no human would have desired to set foot in this area for millennia. Would the British Caving Expedition, who had been searching this area for caves for decades, and had actually spent years searching for this exact cave based on the disappearing river, ever have found it on their own? I don’t know, but other than the blowing mist that emanates from the entrance on occasion, this cave entrance is so well-hidden, it is now very easy for us to believe that Son Doong could have plausibly been hidden from human knowledge for a very long time.
We finally step around a bend in the thick, verdant jungle, and a pile of jumbled rocks awaits us, the cool air softly billowing out from between them. On the stone wall is a painted mural honoring Ho Khanh and his discovery, and we take pictures next to it while the safety assistants prepare our harnesses and strap us in. The entrance to this cave involves climbing over and around large boulders while descending steeply, a slope that approaches 60 degrees in places by my estimate. Ropes are strung along the path, and we clip in with a dual carabiner system that allows us to shuffle safely between rope systems. The stygian depths of the cave entrance seem bottomless, and our anticipation soars as we slowly work our way down, one-by-one. The safety assistants, who by this time have long ago identified the weaker, less experienced, and more timid of our group, hold to their charges, carefully helping them through the more technical or slippery parts. Nobody wants a fall here, which would likely end the excursion for that person.
Tha has informed me earlier that of all the trips he has led through Son Doong, on only one was he forced to send a client back, and that decision was made right here at the entrance. If you are terrified of this descent into the yawning black maw that opens below you, then you will struggle mightily with what’s yet to come, and this is the last easy place to send someone back. After this descent, we will be committed to the full trek through the cave.
Safely at what they call the bottom of the entrance, though we can still hear the river roaring very far below us, hidden beyond our site in the bowels of the rock, we begin our trek through the perpetual darkness. Tha stops to light up the fault line in the rock, the very weakness in the limestone that has allowed this cave to form. The fault line in Son Doong runs the entire length of the cave, more than nine kilometers from north to south and it is visible as a crack and discoloration in the rock at many points.
Time seems to stand still in the stygian depths of this cave that is deep underground, but after some amount of trekking, the river finally rises from its deep bed to meet our path. Ropes are strung across the river for us to hold onto lest we be swept away in the quick current. I would shudder to think of the effort it would take to find a body that fell here, as the river goes over a small, tumultuous waterfall only to disappear once more into the darkness.
We safely traverse the river and then hike for a time through more boulder fields. Flying insects are everywhere, and we have to swipe them from the air in front of us to avoid ingesting them as we breath hard from the exertion. Bats flit about, buzzing our heads and darting in and out of the illumination from our caving headlamps, hungrily swooping up the flying bugs like in a futile, never-ending game of Hungry Hippos. We eventually reconnect with the river which has made a wide bend around the cave, and we cross it once more, the water swift and thigh deep on me, nearly waste deep on others.
The river successfully crossed, it dips down and away from us, and Tha informs us that here it goes deep underground. We won’t see it again for the remainder of the trek, and we bid it farewell as we march onward, its roar muting in the distance behind us. The UK caving team has made several attempts to follow the path of the river, including a few SCUBA dives in an effort to discover what they believe may be yet another cavern on a level below this one, however, success has thus far eluded them, the water too deep and too swift to safely explore. Tha tells us that they once reached a depth of 88 feet in their attempts to dive it, but that was the limit to their equipment and experience, and the effort ended there.
As we trek onward, Redwood-sized stalagmites greet us, their sides rife with rivulets and intricate patterns carved by flowing water. I’ve seen a lot of stalagmites, stalactites, and columns in numerous caving adventures over the years, but I have never seen any that come close to the gargantuan monstrosities that now meet my gaze. Formed by calcite mineralization in dripping water, its often said that the growth of these can be measured in millimeters per year. Tha tells us that the first time he entered Son Doong ten years prior there was a formation of stalactite and stalagmite that was only a few centimeters from connecting into a column, and in that time, it has still not connected. And yet, these stalagmites that we now brush up against and explore are sometimes more than 100 meters in height, with a diameter that oftentimes is more than 30 meters. The ceiling of the cavern often rises more than 200 meters above us, leaving most of the stalactite features out of the reach of our headlamps, even at their brightest settings.
Tha now sets us up for a view of the massive cavern we’re traversing by sending the safety assistants out with their bright, handheld lights, and theatrically calling for the lights to be turned on all at once to illuminate the cavern. Appropriate “oohs” and “aahs” follow, and we marvel at the breadth of this cavern. Far in the distance, a kilometer or more away, the distant light of the first doline can be seen. A doline, or skylight, is an area where the cave ceiling has collapsed, opening it to the light, and Son Doong has two of them, massive in size. Much more about this later.
A feature far in the distance is silhouetted by the light from doline one, and a solitary figure stands atop it, his helmet light turned on, a melodramatic setup, though absolutely magnificent in the effort and the effect. This formation he stands upon is called Hand of Dog, a misunderstanding during the initial survey where protocol dictates that once a name is recorded in the ledger, it is there for posterity, misunderstanding or not.
After resting, marveling, photographing, videoing, and an appropriate amount of awestruck reverence, we continue our trek toward doline one. Difficult at times, but never without constant wonders that leave us with sensory overload, we finally arrive at a promontory overlooking Son Doong camp one. It is 5pm and our stomachs are rumbling, the smell of cooking food already wafting up from the camp below. The porter team and chefs march around like ants in the gloom as they prepare for our arrival, no doubt looking up to see our approaching headlamps and making their final adjustments. The effort these guys put in is something that just can not be overstated, and we were all eternally grateful and impressed by how smooth this Oxalis operation was.
We work our way down the steep slope, daylight from the doline now helping to illuminate the path. Our tents are lined up, waiting our arrival, beckoning to us weary travelers for rest and respite. However, our day isn’t done yet. We’re hot, covered in sweat from the exertion and humidity, a sticky, exhausted mess, and Tha tells us that there is an opportunity to swim here at this camp, however, it will require a 15-minute arduous trek on a very steep path down, a trek we will have to reverse afterwards, meaning significantly more effort at the end of the day when we only want to relax. He also tells us that for this swim, it is mandatory that we swim in the very clothes we’re currently wearing, shoes and all, and that we will have to wear life jackets the entire time.
While none of this sounds all that appealing, I am a sticky mess, and the opportunity to actually wash some of that off me is irresistible, even if I will get sweaty again afterwards on the long climb back up to camp. I’m also unwilling to miss even one inch of what they will allow us to see of this cave, regardless of the effort involved.
We drop our packs at our tents and then the group splits up, with Justin, Ly, Phuong, Damien, Tracy, and I deciding to accompany Tha, Hieu, and three safety assistants to the swimming hole, and Anthony, Truc, Jeremy, and Kay electing to stay at camp and rest their weary limbs.
We leave camp, dropping off the large sandy shelf that contains our home for that night, and back into the dark depths of the cave, working our way across the massive chamber and toward the far wall. As we descend steeply downward, I begin to question my decision, imagining a quick dip in some stagnant lake followed by a tough, sweaty climb back up. After all, the river is deep underground at this point in the cave, supposedly lost in the bowels of the earth, so how could this swimming hole be anything of interest? I could not have possibly been more wrong. In my defense, Tha and the others were strangely reticent to share details of this upcoming adventure, an unusual taciturnity for the normally loquacious crew. That should have been a sign…
Passing many unique and interesting rock and mineral formations, as well as some fossilized crustacean remains along the way, the much less-trodden path winds its way deep into a crevice between the floor of the cave and the gargantuan wall, descending down far out of view of the light from doline one until it feels that we have traversed into another world entirely, dropping down toward Hades, or perhaps marching toward a date with an imprisoned Balrog. Stopping on a smooth but steep rock, Tha rechecks our life jackets, allows us to remove our caving helmets, and then leads us into a narrow passage through what seems to be uninterrupted rock until…viola! A narrow crack in the rock appears in the light of the guides’ handheld flashlights, hundreds of feet in height, the walls sheer and stretching upward to disappear in the inky blackness. The crack is filled with an aquamarine water, pools that are refreshed by floods of the river far below but remain almost hidden from all light for eternity. One-by-one, we slip into the frigid waters with whoops and shouts of joy, our weakness and soreness completely forgotten as the icy waters soothe our tired muscles and we swim away from the launch point, following the flooded crevice back along the length of the wall. The safety assistants turn on waterproof lights and dip them below the surface, revealing the deep blue-green of the incredible water. I scrub the accumulated sweat and silt from my head, reveling in the refreshing bath, and even Tracy, who normally loathes cold water, is enamored by the icy plunge.
The six of us clients plus Tha and Hieu gather at the far end of the pool where a rock shelf has dipped into the water allowing us to stand, and Tha shouts down to the far end for all lights to be extinguished. We marvel at the pure darkness that engulfs us, an absolute absence of light where one can truly see nothing, and in my head, I imagine trying to find our way back to camp if the lights fail to turn back on, a nightmare scenario that thankfully fails to come to fruition as they click the lights back on and we continue to frolic in the pure refreshment of this miraculous pool.
“The only question I have,” I announce to the others as we languish in bliss while some of the group begins to shiver in the icy waters, “is how do we tell the others who stayed behind, that they missed the best part of the trip?” Everyone laughs, but they all know that I’m only partially joking. This experience, if any readers are lucky enough to go on this tour, is an absolute must, not to be missed for any plausible reason.
Eventually, the frigid water drives us to swim back to the entry point where the safety assistants wait to pull us back up to the launch ledge. We squeeze through the narrow passage under the rocks and marvel at how this hidden oasis was even discovered in the first place as we reach the spot where our caving helmets and lights await. The long, steep climb back to camp in wet clothes does indeed leave us tired and a bit sweaty, but we all agree that the magnificent experience was worth every ounce of expended energy.
Dry clothes and a steam bath await us at camp, and we convey far less than the exuberance we feel in our description of the trek to our fellow travelers lest they feel they’ve missed something truly spectacular. Which they have. At this point, I’m exhausted, the cold water finishing off whatever energy hadn’t been used up in this day’s trekking. Dinner is served at 7pm exactly, another cornucopia of absolutely delicious meats, soups, vegetables, and various rice dishes. I honestly can’t tell if the food is so good simply because we’re exerting so much effort, or if the chefs are just that good, but it doesn’t matter, the fare laid out before us in at least seven courses is fit for the banquet halls of even the most prestigious kings, and we lay into it with gusto, once again failing to even come close to polishing it all off. The calorie burn of this trek should leave us all with a good amount of weight-loss, but I believe we’re probably easily replacing those calories with the magnificent feasts provided to us for each meal.
After dinner, we sit and relax around the charcoal campfire, watching as the light fades from the doline and darkness descends upon the camp. The chefs and porters clean up and then the porters retire to their area away from us where they play card games and lounge around relaxing. One of the chefs brings a grill top over to our charcoal fire and then loads it with sweet potatoes which bake over the coals, a delicious desert that is hot and bubbling 45 minutes later. I somehow manage to stay up until ten o’clock tonight, a record for the trip and an unexplainable achievement based on my exhaustion factor.
Sleep eludes me tonight for all of about two minutes before I’m dead to the magical world in which I’m enveloped.
Author Rick Fuller 