Largest Cave Chamber in the World: The Sarawak Chamber

Largest Cave Chamber in the World: The Sarawak Chamber

What makes for the World’s largest cave?

If a combination of height, length, and width are the variables we’re looking for, then Son Doong cave in Vietnam is number 1, boasting its own forest ecosystem inside. However, one can expect a margin of light to follow them through Son Doong’s unbelievable recesses. To truly find the Earth’s largest enclosure, where headlamps are about as effective as birthday candles, they must head to Mulu park in Sarawak province, Malaysia.

The Sarawak Chamber is the globe’s largest (discovered) enclosed space by area, though it’s beat in volume by China’s Miao room (in Getu national park, which I’ve written about here). The adage goes that more than several 747 jets could be placed wing-to-wing in the chamber, never touching. To supply a description of its size with superlatives is borderline pedantic; Imagination can hardly do the job.

Sarawak chamber
From a previous expedition, showing a small portion of the chamber

My two good friends and I recently signed up for a tour that would lead us to the Sarawak Chamber. We were all lucky enough to beat the water level (which rose to unmanageable the very next day) and make it into the cave.

Sarawak chamber
Heading in near the entrance

Mulu caves require bookings in advance, as well as a deposit of some 300 ringgit for the more advanced systems (those being Clearwater, contender for the world’s longest, and Sarawak). Ignore any tour operator that isn’t the park’s own service – the cheapest and safest options for exploration come from the park’s own guides.

Head to the website and click tours and activities, and choose Sarawak Chamber Overnight at Camp One.

Sarawak Chamber

Your inquiry message should specify the number of people in your party (minimum allowed is 3) as well as if you have documented caving experience. If not, you’ll need to complete the intermediate racer cave the day before the Sarawak Chamber expedition (signing up for just the Sarawak is kosher – so long as you specify that you need to qualify they’ll book it for and send you email confirmation).

If the water level is too high when you get to Good Luck Cave (Sarawak Chamber’s location), a definite possibility, you won’t be allowed in. Bookings can be made for successive days in case this happens, or you can opt into another adventure cave.

What you’ll want to see – a trickle

You’ll pay the deposit with a credit card or by using

Luckily, it’s possible to pay for both caves with a credit card at Mulu Park headquarters. Your deposit will go for Racer cave at 165 Ringgit with the leftover being used for The Sarawak Chamber or other tours you opt into.

Racer Cave
Racer from the approach

Be forewarned that there’s no way to get money in the park proper – no currency exchanges and no ATM’s. This came as a source of contention for my friends, myself, and many other travelers. I ran into a couple who announced their woes of being penniless to another party, and I watched as those travelers responded with a gift of two rambutan (a less than satisfying meal).

Don’t get caught in the proverbial rain regarding money here – there’s enough of the real thing to keep your boots soaked, anyways. Bring at least 1000 Ringgit for a week just to be safe.

I found out about The Sarawak Chamber online, and by proxy about Mulu Park. The rest of the information I gleaned came from the park’s website. Beyond bookings and inquiries, it’s all rather vague. You’re not going to get information about what your expedition will look like unless you ask for it, so find park staff upon landing and get ready to lay down some questions.

Racer Cave, the intermediate system used to determine your mettle, is a wonder in of itself. It’s remoteness resulted in a rather late discovery of the system – the 1990’s. Our guide, a local named Ravi, told us that it was his grandfather who’d stumbled on it while boar hunting.

Racer cave
View on the way to racer

The tour starts at headquarters. You’ll suit up with a harness (that only gets used once) and a helmet. Expect a 30 minute boat ride and wet feet (you can reasonably assume your feet will be wet for the duration of the trip, or at some point at least). The cave climbs up a muddy slope of scree, unstable and slick, before opening up after a comfortably tight squeeze.

Racer Cave
Top of the initial slope

There are two things one wouldn’t expect to chance on in a jungle cave – crabs and seashells. Here Racer defies expectations; blind crabs sulk through puddles of water, feeding on bat guano, and fossilized seashells can be seen jutting out of a small indent in the wall adjacent. Geologists have determined that Mulu’s caves were carved out by oceans.

Racer cave
Behold – Seashells

The cave’s nomination has nothing to do with speed. ‘Racers’ are actually snakes that inhabit the cave in impressive numbers. Coiled in nooks and slinking across the silted mud, you’ll be hard pressed to avoid them. Our guide, Ravi, wasn’t keen on snakes. It probably didn’t help that the racers were poisonous.

Other attendant poison cave-creatures include the long-legged centipede and the huntsman spider. Our group had just moved past the grotesquerie of such a centipede when Phil and I happened to look back. Dillon, in the manner of a secretive and excited child, was moving his finger slowly towards the beast. As the final inch of space closed between himself and the thorax, we hissed out his name in hushed whispers, trying to keep him breathing without alerting the attention of the guide.

Not a terribly inviting creature

Managing to look both dejected and guilty, he skulked back to the group.

Four series of old ropes safeguard the passages with vertical inclines. You’ll need to flex up and keep taut to the wall, which would be no picnic for the physically inactive. Expect the watchful eye of the guide to follow you down obstacles, probing for weakness.

Caving in racer

Dillon’s obliviousness to the dangers of being poisoned in a remote cave came to a head near the end of the passage. A racer was on the move, stopping on a little table of rock to assume a coil. Ravi urged us, his own fear of snakes bringing out a pleading in his voice, to keep a distance. Getting just within striking distance of the reptile, Dillon snapped a selfie with it. The bulge of Ravi’s eyes at this display was exaggerated by the shadows of our lamps on his face.

Racer Cave
The selfie in question

The end of the cave flares out in all directions to form a large room wrung with hills of dirt and swimming with bats. Water drips, erosion still wearing at the cave with a glacial slowness. The luminescent eyes of huntsmen spiders, who grow larger than the size a formidable man’s hand, fire up in the light of our searching lamps. It’s quiet beyond the muffle of flapping bats.

racer cave
Take one guess as to whose finger this is

You won’t be told whether you’ve qualified until after getting back to Mulu HQ. Qualification seems to encompass a number of things, not just your physical ability. If I had to conjecture, I’d say they were as follows:

 Respect for the cave – not touching any wildlife or dislodging things purposely
 Physical ability – navigating obstacles without hurting yourself
 Following directions
 Attitude – avoiding overconfidence

Every other person in our group qualified without incident. When Ravi looked at us, he turned his head and let out a sputter. His eyes were skeptical.

“You three, there are some problems”. Phil and I looked at Dillon.

on the way to racer
“Us, you say?”

“But you’ve qualified”.

We were not about to ask what the problems were.

As stated prior, there are a few things they don’t tell you about the chamber on the website. First, and most annoyingly, you don’t get to enter the actual chamber. Beyond that, you don’t even get to look inside of it, which is particularly disappointing especially in light of the website description, which reads as follows:

Sarawak Chamber
As close as were allowed to get
 “Following the traverse the tour then proceeds up a steep boulder slope to the chamber itself (takes roughly about 120 minutes to complete).  The chamber is pitched at a steep angle and the floor is covered in boulders.  The tour stops at the mouth of the chamber.”

One of the first things our guides told us is that we’d be stopping at ‘The Japanese Camp’, an arbitrary location before the final slope that leads to the chamber (apparently not a camp either; the Japanese in question had gotten tired and stopped there before turning back. No camping took place).

The reason cited for stopping before the chamber was that bane of adventurers on guided trips everywhere: Safety. Apparently, the slope before the chamber mouth is given to landslides, which could be triggered by 5 people moving in a line up the hill.

We pointed out the fact that we didn’t have to move in succession on a fixed rope; it’s not Everest, after all. And that the contract keeps the park free of blame for accidents. And that the slope really doesn’t look all that precarious and I mean look at how fit and enthusiastic we all are (ignoring our calves, probably the factor that kept them from letting us bend the rules).





No avail. The Sarawak Chamber tour stops before the Sarawak Chamber.

Many are probably wondering why the tours here are so cheap, especially considering Sarawak involves two guides and an overnight stay on Mount Mulu’s camp one. The answer lies in another fact that isn’t mentioned online – you need to bring your own food and the gas to cook it, as well as a pillow and sleeping bag.

Alternatively, find your own food in the jungle

You can buy the food and the gas to cook it (only slightly pricey) at the general store and rent a blanket at headquarters. Be warned, though. The ‘blankets’ (15 ringgit deposit) are little more than squares of fabric your Grandma’s knitting circle would scoff at. They’re suitable for covering either your legs or torso, but certainly not both. Camp one consists of sleeping mats and a wood floor. Bring a makeshift pillow or suffer.

Apparently, it’s also a possible to return to camp if you don’t emerge from the chamber too late. The less intrepid can opt for this, but camp one is great for catching views of Gunung Api (domain of Mulu’s famed pinnacles) in morning sunlight.

Api in afternoon light, as not to spoil it for you

Once equipped the hike starts from a marked trail, meandering after a few miles across the first of many rivers. The foliage is dense on the way. The trail begins looking more suited to wild boar than trekkers.

Our guides are fellows of quick feet and few words. We three would often fall behind, stopping to appreciate or gawk at something, and they would simply disappear.
This may be annoying to some, but we found it rather freeing. The crushing watchfulness and views from askance make North American wilderness guides a tedious bunch to be around, sometimes. Even the most experienced can feel inept among the piles of regulation there. This is not the case in Mulu.

The hike is littered with wildlife because it sees few visitors. Most of what you’ll be up close with are leeches. Keep an eye out and pull them off before they stop your blood from clotting. Contrary to what we thought, it’s not the water that they’re partial to, but rather the forest floor. The area past the MULU SUMMIT THIS WAY sign seems to be the only place where the leeches are, so you’re fine elsewhere.

Lunch is cold, as the guides don’t carry stoves. Those are reserved for camp one. Ask your guides (seriously, do it) to find the coconut-looking fruit in the mango family. It’s just about the tastiest piece of jungle cuisine you’ll get your grubby hands on (see previous photo).

The chamber, after what seems like bushwhack-guesswork (and is more than the stated 3 hours hike away from HQ), is situated in Good Luck cave. The opening is unique in that its quite narrow and dizzyingly high. A small river rushes out. Bats frenzy around the concave upper reaches of the mouth.

Here you can leave your valuables without fretting about whether they’ll be stolen or not. No one else is going to be following you in.

We’re studded with helmets and waterproof headlamps. At most angles Dillon resembles a construction worker after a long, hard day (Phil’s words).

Sure is a pity when a water main bursts

Phil’s got his phone ratcheted to his headlamp and looks vaguely like air-traffic control.

The water starts at your ankles, a silty mess, before the last triangles of light fade into an increasingly yawning chasm. The river widens, deepens, clears, washes the jungle sweat off of soiled bodies and clothes. In fact, this was the purest water I’d ever experienced, reducing what felt like a fever outside to a warm trill of exultation throughout the body.

We wade and traverse across ropes or paddle lightly through ebbing currents. As elevation gains and the cave continues to heighten, with the expansion of its sides following suit, small waterfalls careen from above, easily traversed by taking hold of the rock-jug handholds on the nearby cliffs.

Walls of rock soon give way to formations that can be scaled and descended at will, and anyone with a back round in climbing should find the expansive nature of possible traverses heartening. Overhangs and head-walls and sharp limestone stalactites juxtapose the depths of turquoise below. Our guides are more than happy to let us climb and swim as we please, taking our time as they blast out ahead and wait.

Leaving the stream behind you’ll traverse left, gaining ground on muddy and sharp rocks until reaching a boulder-hewn slope slick with mud and debris. Aggressive stepping will land you face down in the dirt after spraining your ankle, so make slow and careful progress.

Once at the Japanese ‘camp’ we’re forced to stop. We can see, with the help of all our headlamps, that a more precarious slope lies just ahead, rung around the top by an opening large enough to accommodate a commercial blimp. This is the mouth of the Sarawak Chamber, the closest we’re allowed to get to the World’s largest natural amphitheater. We beg, plead, harangue, insult – all to no avail. We won’t be allowed in.

Yet, the stopping point’s a large enough room to provide a feel of what the terrain ahead holds. There’s so much space that it ceases to feel like a cave – the close, musty embrace of deep-cave air is absent here. It’s almost breezy. With all the headlamps out one could stir up the illusion they were laying under a dome of night sky, the glowing eyes of a huntsman spider passing for distant stars.

The Japanese Camp, with the chamber’s mouth hidden up a slope behind us. The room here is also too large for headlamps to make a dent

Apparently, regular expeditions mounted by (mostly British) caving teams are allowed into the chamber. Our guide is adamant that we would be allowed to join one should we like, since most of the parties are full of aging scientists. For Phil and I (Dillon’s pregnant wife would likely have other ideas for his traveling future), this was good news. This seems to be the only way (besides sneaking in, which I guess is possible) to get into the chamber as a layman.

I’ve since contacted the British Caving society and have yet to receive a reply, though I’ll continue to bother them as time moves along.

Our guides, midway through the cave, implore us that Clearwater would have been a better, more adventurous (and longer) option, wondering aloud as to why we chose Sarawak when you don’t even get into the chamber itself.

Though disappointment may have been our reaction on paper, it’s truly hard to muster up any real discouragement in the midst of spelunking. Size is insignificant to the general awe that one accumulates when finding themselves so far removed from society, mountain-deep in one the world’s most spectacular caving locations.

Apparently, only upwards of ten people venture into this cave every year. Even without the chamber proper I would encourage anyone to do this tour.

Final glimpse of Good Luck Cave

We’re told that there have never been any caving deaths in Mulu, and that no injuries had taken place in Good Luck cave since the qualification system had been introduced. This should come as good news to those whose families and busy gnawing their fingernails to the quick as sons and daughters head off to explore Mulu’s caves.

We make it out quickly in hopes of radioing headquarters, to set up Clearwater connection (another large cave) for the next day. If there’s space on expeditions, you can book them while you’re at Mulu, though we found no such luck. We figured we’d head to Camp one instead. It would be good fun, a real jungle experience.

There is nothing fun about camp 1 if you don’t bring your own blanket. A few notable quotes from the boys at about 2:30 AM sum up our sleeping experience nicely:

“I laid down on a ******* anthill, they’ve been crawling on me all night”.

“I just want it to be over (whimper)”. We’d laid down to sleep at 8:30 PM.

Again, it’s possible to return to HQ if you get out fast enough, but there’s no reason to privilege speed over an enjoyable experience. We weren’t racing and we made it out well before the sun had sunken away. Camp one, at least, is situated uphill from poignant river, great for bathing.

Your guides may have you depart before them in the morning (or maybe ours did only because they’d gauged our comparative speeds). There’s one or two forks in the trail, as well as two or three river crossings, that can easily befuddle. I’d taken pictures the day previous in an attempt to mark the trail (we were noncommittally thinking about sneaking back to Sarawak to solo the chamber, an idea that was abandoned soon after inception) on the way.

As it were, we ended up in a river bed that eerily resembled one of the photos I took after the trail had turned towards the Sarawak Chamber. Lo and behold, we were lost.

Our picture to mark the trail, when hopes of illicit entry still endured

After ten or so minutes, one of our guides came sprinting through the jungle. He pointed and stayed just far enough ahead that we almost lost him on the way back to salvation.

Any sort of discomfort endured on our part paled in comparison to the cave. Torrential rain, leeches, sleeplessness – these were minor accouterments of fate, the bare minimum of price to be paid for the experience. The cavern’s cathedral height, iridescent water, baptismal falls, congregation of bats – all enough to stop time and erase thoughts, to ring in testament to the now.

While I cannot speak to the value of other adventure caves, I’d recommend the Sarawak Chamber to anyone looking for something unique, isolated, and record-breaking.










5 Replies to “Largest Cave Chamber in the World: The Sarawak Chamber”

  1. So much great I information about an incredible place I’ve never been. Your adventure and advice makes want to book a trip asap!

  2. All I can say is I read your answer to a Quora question and read this after. You are truely inspirational in terms of actually living a life to its fullest! All these hidden gems that only rare few have the courage to see, is awe-inspiring. Thanks for sharing with the rest of us!

    1. I’m excited to hear that I can inspire people to strike out and do the same kind of things! Thank you for your comment.

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