Malaysia, Sarawak
Malaysia, Sarawak
by Jan Brelih
May 31, 2024
"A sound recording expedition into one of Earth's most biodiverse yet most threatened and exploited natural environments, discovering the untouched lands that still exist deep inside the Heart of Borneo."
Photos taken about 150km away from the Borneo coast, at least 100km away from any real (already remote by itself) road, village, market, or anything that could be classified as civilization. We are hundreds of kilometers inside the Borneo mountains, covered by thick jungle.
Even from afar, the devastation of Borneo is obvious—a network of logging roads that penetrates even the most remote corners of the island, in the shape of roots, carving relentlessly into the landscape. Despite its massive size, precious few bigger areas remain truly untouched. What’s left of easily accessible rainforest survives only in isolated fragments or within the strict boundaries of national parks such as Mulu or Maliau Basin. These protected sanctuaries, while crucial for biodiversity preservation, impose very limiting restrictions to fully experience wilderness as I always do: designated trails only, mandatory guided tours, no camping, limited availability, and such. For someone who is used to the genuine feeling of self-discovery and independence, such official constraints are presenting a substantial barrier to my very purpose.
The alternative lies deep within Borneo’s vast interior—the Heart of Borneo, as it is called, is basically a mountainous range stretching from north to south. Nothing is mapped, official, or discovered much; only vast mountainous landscapes, tiny local villages, and, unfortunately, extensively logged areas, especially on the Malaysian side. These lands remain largely unknown because of their remoteness and difficulty of access and are completely beyond the realm of conventional tourism. This is the path that doesn’t even cross the minds of most people. Mostly local adventurers venture here, as they know about this (limited) possibility. For me, it represents the only inspiring opportunity: the freedom to roam, exploration of the unknown, audio documentation, and getting to know about authentic local life.
The approach of identifying the most suitable and unique areas for sound documentation starts for me well before the field trip. I do extensive analysis of digital maps and look for any accessible information online, such as research papers, though it’s usually scarce or nonexistent. The main focus is finding areas that remain completely untouched, unexplored, and are substantial in size.
While researching Borneo online through maps, a certain geological formation in Sarawak caught my attention. Switching to the terrain map, I realized it is a massive plateau rising above the landscape, deep within the Heart of Borneo. When viewing satellite view, it seemed that this entire area is still covered by intact primary forest, a rare sight nowadays. Although logging roads were already reaching some of the lowland forest below, the plateau appeared completely untouched – a pristine area of 490 km². This has now really sparked my interest and become an obsession to learn all about it and eventually try reach it.
Usun Apau is an ancient volcanic plateau covering 490 km² in Sarawak, at about 1,000 meters above sea level. Formed 3.9-4.1 million years ago, the plateau is dominated by three extinct volcanoes – Selidang (1,370m), Kenawang (1,280m), and Mabun (1,280m) – forming a triangle in its center where clouds gather and rainfall concentrates. What makes this landform striking are the dramatic cliff edges that drop 300 meters along its northern, eastern and western boundaries. These escarpments create spectacular waterfalls, including the 100-meter Julan Falls and many still undiscovered. The plateau serves as a critical water source, feeding three major river systems – the Baram, Balui, and Tinjar – that sustain much of northern Sarawak.
The landscape features unique forest types growing on volcanic soils, including mixed dipterocarp forests in valleys and unusual kerangas (heath forest) with thin-trunked trees and twisted roots spreading across the ground surface. This geological and biological diversity creates a mosaic of habitats receiving over 4,000mm of rainfall annually.
Usun Apau holds profound cultural significance as the ancestral birthplace of the Kenyah people. According to their oral traditions, their communities originally descended from this mountain plateau, making it a sacred place in their cultural heritage. The name itself reflects this importance – in the Kenyah dialect, “Usun” means “on top of” or “further up,” while “Apau” means “plateau.”
It was officially designated as a national park in 2005, but no formal management infrastructure exists yet. Perhaps this absence of development helps preserve its pristine nature. Most people, even locals, don’t know about it, yet it represents Sarawak’s third-largest terrestrial protected area. Recent scientific expeditions continue making remarkable discoveries here, including the first-ever orangutan sighting in 2020 – previously thought absent from this elevation – highlighting its importance as one of Sarawak’s last intact wilderness areas.
"Sarawak has lost approximately 80% of its primary rainforest since the 1970s, with only 5% remaining intact. Over 3.5 million hectares were cleared between 1990-2020, primarily for palm oil plantations. Protected areas cover just 6% of the state, yet many lack active management. In this increasingly fragmented landscape, remaining wilderness areas like Usun Apau have become critical refuges for biodiversity."
Field recording a very unique ambience on the 1000m high plateau, Usun Apau, Sarawak 2025. Deep in the Heart of Borneo.
Going here presented significant logistical challenges due to its remote location deep in Sarawak’s interior, mostly regarding finding the (independent) transport. I identified a viable route over the logging roads from Miri town to an access point for the plateau. However, relying on any official local transportation turned out to be not so straightforward—any transport services were very rare or expensive for what would essentially be a one-way journey, while motorcycle rentals (unlike in other Asian countries) were either nonexistent or restricted to city use only. After field recording all across Thailand and Cambodia for the past 5 months, I needed to carefully manage my remaining funds. Facing such conditions, I needed to think smart and think of realistically possible transportation apporaches.
After brainstorming options in Miri, I discovered there is a small local plane connection flying to some remote interior villages. While it wouldn’t reach the plateau directly, it would get me closer. I booked the ticket, and after a few days I was on my way. During the flight, I watched the landscape transform from endless palm plantations across all lowlands into jungle-covered mountains. I spent several days in the village recording my first Borneo jungle sounds, meeting locals and getting a feel for the area. Though friendly, most villagers had abandoned traditional forest-connected lifestyles for more modern lifestyles, disconnected from the jungle. True traditional longhouses maintaining deeper relationships now exist only in the most remote, isolated areas—further from logging roads. Finding transport to the plateau proved difficult—no viable local jeep opportunities existed, and river travel had been largely abandoned for pickup trucks. After a few days—actually beautiful days getting a first glimpse of the island interior—I realized I needed a new approach and decided to return to Miri by hitchhiking via the logging roads.
On the left, a local Kenyah from the village, he invited me to put my hammock at his place. While hitchhiking, I met the people working on the front lines of deforestation – the loggers. They even gave a ride for hours over the logging roads. I’ve realized, you know, these are just people doing their job. Actually, I was greatly impressed by their skills and what hard and dangerous work they actually do, even if it destroys nature. Strangely, somehow they have been the kindest and most good-hearted people I have met. Maybe one day they can become guardians of the forest and apply their knowledge to something sustainable. It is difficult to judge.
This expedition was taken with an exploration approach, learning and finding the best way as I go. Such challenges can be expected, and you need to be ready to overcome them. It is like a complicated puzzle, coming together slowly piece by piece.
Here, the biggest challenge was finding an actual vehicle to rent. Even paying above-average rates, no rental company will give you a 4×4 vehicle for off-road use. After days of talking to many different companies and getting the same negative answers, I have finally found someone who was potentially ready to rent the pickup for going on the logging roads. After much reassurance about my driving abilities and agreeing to specific conditions for a higher price, we finally got the car! I have actually ended up connecting with a fellow field recordist in Miri by chance, and he will now be joining me for a part of this trip.
Finally, I had my own transport, a Mitsubishi 4×4; it felt great! It seemed like my plan was becoming reality. Then came the real deal: an absolutely brutal 8-hour drive from Miri to the interior, covering about 140 kilometers of treacherous roads. These weren’t just some average roads; also, recent rains had turned them into slippery, muddy mess that slowed us down constantly. Just getting to where we needed to be was already a whole adventure by itself! I could write pages about these roads and how people actually travel out here. We were definitely sticking out here—every local driver we passed looked at us with amazement, while at the same time being impressed that some foreigner was actually here driving on these roads. If the road conditions were not enough, we had the available 4×4, but it had regular road tires! At times I thought that we could not make it, but with my determination and utilizing my driving skills to the limit, we proceeded towards the deep mountains within the Heart of Borneo.
The forest on the top is very different from the one below, with much smaller mossy vegetation yet that gets broken by still massive ancient trees rising above.
From here, the second phase required a challenging 12-kilometer trek to reach the plateau. Unlike established trails in more typical natural areas, approximately 80% of this route couldn’t be classified even as a basic trail. Overcoming the way involved extensive bushwhacking through dense undergrowth, navigating unmarked terrain with experience, and scaling steep sections to the plateau edge. The challenging fun of driving has been exchanged for a more physical one.
Early morning brought our first expected task: reaching the trail 3km from the only inhabited house in the area, where we’d leave the 4×4 for safety. We waited for someone to pass by, yet nobody appeared that morning. Locals travel these roads to reach remote villages. Not wanting to lose time, I drove back to find someone who agreed to transport us for 300 ringgit (60€) for 15 minutes of driving – we negotiated a bit. As we entered the forest, it was a confirmation that this will not be an average journey. Fallen trees, head-high ferns, and an invisible path immediately confronted us. Within 15 minutes we crossed a massive landslide and broken bridge, realizing we were following what must have been an approximately 30-year-old logging road. This made it harder to navigate than the deep jungle, where giant trees prevent undergrowth. Forget about the rain or sun; you are completely soaking wet with sweat —it was not fun. We realized there are clear water creeks every 20 minutes, which was an absolute heaven for drinking and cooling off. After 4 grueling hours, we glimpsed the plateau! Heart racing from both physical strain and excitement, we camped on the ridge overlooking Usun Apau’s valley. Here my friend decided to stay here for a night—tomorrow I’d continue the ascent alone.
I woke up at about 5:00am to capture the morning chorus of the forest under the plateau. Soon after, I start to pack up my camp and start up early. I needed to reach the plateau today; the way was still long and unknown. Just a slight descent, and I have reached the junction where two rivers join. After crossing and looking for the right way, I continued on the trail, which now was going more uphill. I finally reached the hardest point of the whole trail, a 1 km section of nearly vertical wall of the plateau, a final section. At this point I am completely exhausted, climbing with a 20kg backpack and stopping every few meters, with some moments of getting seriously dizzy from all the heat. After about 1.5 hours, the terrain was starting to flatten and the surroundings had started to shift, and I had finally reached the top of Usun Apau.
"Crossing onto the plateau revealed an entirely different habitat. In just 100m , the lowland rainforest transitioned into a mossy montane forest with smaller trees and vegetation, while in between were still ancient giants rising high above".
As I caught my breath and set up camp, there was no time to lose. I unpacked and set up my recording gear, feeling amazed to start capturing all the unknown sounds hiding here. It is always such an exciting moment when you reach a completely new habitat, not knowing how it will actually sound. Here, I was expecting a very rich acoustic diversity; however, as I positioned my microphones, began recording, sat in silence, and truly started to listen, I realized something. The plateau was remarkably quiet. I guess so, as the whole forest ecosystem changed drastically, so did the whole acoustic image. Well, it was still the middle of the day, and who knows what the dusk, night, and morning will bring? For most of the day I was around my hammock and the always-recording mic setup, soaking in and learning about this special place. As the dusk approached, there was not much activity, but the one that I was in was very unique, with many types of sounds I have not encountered before anywhere else. Being all alone here, at night, in this primeval place far away from any civilization was one of the most profound and deep experiences I’ve had during my expeditions; you cannot put it in words. The night soundscape was an amazingly unique, mysterious, and balanced ambience that represents this place in a very true sense.
I wake up just before the dawn and check that my rig is still recording. All good. This is the first morning on the plateau, and I am excited to experience the morning awakening of this place. Below in the lowlands, each morning is very vibrant and congested with all sorts of birds. When the first small light in the sky emerged, there really wasn’t much of a sound. It was a very, almost eerie silence. I was quite surprised to be so quiet here, as the habitat seems so diverse and completely primeval. That being said, I did capture some very unique, never-before-heard sounds and some isolated cicadas that were very unique with high isolation from other background ambience As the day was progressing, I faced a choice. To stay on the plateau hoping to find interesting sounds within the silence or descend to where the lowland jungle vibrated with rich tropical acoustics. Seeking more diverse sounds for my library, I decided to spend another night back under the plateau cliffs, where the ecosystem was more abundant.
"The acoustic environment here was much less active than below the plateau, but within that silence eventually emerged some very unique, never-before-heard sounds. The less congested soundscapes also allowed for capturing clean, isolated recordings—like the highly specific cicadas. Overall, a success."
I woke up with a sunrise; it must have been one of the very first ones in my Borneo journey during the monsoon season. The rays had filtered through the canopy, and there was beautiful birdsong—the whole ambience was rich with hornbills flying, gibbons singing, and many other birds creating a chorus. I was still pretty tired and crushed, but it was feeling really magical. These are the moments of deeper immersion, the most pure and beautiful life, making it all worth it. I set up my equipment to keep recording in the distance while slowly packing my camp, preparing to return. Knowing it was the last day and moments of deep Borneo wilderness, for now, I stopped, sat down, observed, and being grateful.
It was 10:00am; now I was packed and ready to trek back. It was another 4 hours of struggling to overcome all the vegetation and non-trail parts, but I knew that with every step, I was coming closer back. I returned to the logging road and tried to wait in the shadow. Oh yes, the day was completely sunny for a change, full on. Interestingly enough, that brought different conditions—it was very, very hot and humid, and just being a few minutes under the sun felt like being in an oven. I think if I were to do this trip during the dry season, it would be much more difficult for other reasons.
When back on the logging road, luckily a very friendly local passed by and picked me up to take me back to the house where my friend, locals, and 4×4 pickup had been waiting. Once I arrived, everyone was very excited, impressed, and happy to see me come back alive. Very few people really go up there to the plateau, even fewer by themselves, and even fewer foreigners. It felt like coming back from battle. I was very tired but feeling deeply connected.
The way back was pretty surreal: to sit back behind the wheel of the 4×4, comfortably with the AC on and all my gear packed, knowing that I had just successfully pulled off the biggest and most challenging field expedition so far. The road conditions were now completely dry; you would think that would highly improve driving, but now it was another factor of danger. The road was very dusty, so when a car or truck passed, everything was inside a big dust cloud. I have dropped off my friend as he was going to Long Akah, where I have previously gone with him. I continue to drive back across the mountainous landscape, knowing it was the last moment being here surrounded by raw wilderness. I contemplated life and what I am going to do now after this. In some ways I would just go back and disappear into the jungle forever , but I am not finished yet here in this world. I knew I was coming back, dear land of Borneo.
A pool before the big 100m drop of Eastern Julan waterfall descending from Usun Apau.
Usun Apau stands as living proof that intact ecosystems of Borneo still exist. The pristine soundscapes I recorded represent sounds few people will ever hear firsthand. Each dawn chorus captures the voice of wild Borneo—sounds becoming extinct across the island.
The contrast is stark—kilometers of devastated landscape leading to this untouched sanctuary. Usun Apau’s remoteness has been its salvation, but isolation alone won’t protect it forever. This creates a philosophical challenge: How do we study these places without destroying the very isolation that keeps them wild?
I’m committed to sharing these recordings with conservation organizations and research institutions working towards the good for the Heart of Borneo. Every piece of evidence matters when the window for preserving places like this is closing rapidly. The question isn’t whether such places deserve protection, but whether we’ll protect them before they become mere memories. I want to return here with a team of other local researchers, possibly with the access of a helicopter, to explore and document further areas of this massive, unexplored plateau..
First Bornean orangutan sighting in Usun Apau:
https://www.sciencedirect.com/org/science/article/pii/S1314283621002517
Usun Apau Waterfalls:
https://www.waterfallsofmalaysia.com/141julan.php
Expedition of 2012 publication:
https://www.researchgate.net/figure/Satellite-map-showing-the-location-of-Usun-Apau-in-relation-to-the-Dulit-Range-and-the_fig2_273696487
Did you encounter leeches, I love Borneo X
Hi yes, there were some leeches, but nothing too much to worry about. Borneo is special.