Gunung Mulu

Page Type Page Type: Mountain/Rock
Location Lat/Lon: 4.05083°N / 114.93041°E
Activities Activities: Hiking
Seasons Season: Summer
Additional Information Elevation: 7795 ft / 2376 m
Sign the Climber's Log


Gunung Mulu from ridge between Camp 3 and Camp 4Gunung Mulu from the southwest ridge of the peak.

Gunung Mulu is located in the state of Sarawak in the Malaysian portion of Borneo.  Geographically, it has a number of cool distinctions.  It is the second highest mountain in Sarawak behind Mt. Murad which can be seen in the distance from Mulu’s summit in good weather.  It is the second most prominent mountain in Borneo; rising a total of 2,024 meters from its saddle with Mt. Murad.  It is the highest point in Mulu National Park which is an amazing UNESCO World Heritage Site famous for its caves and amazing botany.  With that said, Mt. Mulu, unlike much of the park, is composed of sandstone and shale.  It is perhaps the hardest peak that I have climbed with a maintained trail reaching all the way to the summit.  Expect to see lots of mud, rope assisted cliffy sections, and despite its modest summit elevation of 2,376 meters, probably about 3,000 meters of elevation gain given the many ups and downs along the way.  Did I talk about the leeches?  Needless to say, the climb is loads of fun if you’re into the sorts of things that I just mentioned.


Plaque at SummitPlaque recognizing Tama Nilong
There were a number of unsuccessful attempts to reach the summit of the peak in the 1800’s including by Charles Hose, an entomologist who has a mountain range and a pygmy flying squirrel named after him.  The first successful summit climb was made by Tama Nilong in the early 1920’s.  He was a rhinoceros hunter and these creatures used to inhabit the high boggy lands around Mulu’s summit but are now extinct from the region.  The line of ascent that he found, the south-west ridge, is still the standard route used by people to this day.  Interestingly, Tama Nilong later led Lord Shackleton (son of the man who spent time in Antarctica) to the summit.  Following this ascent it was widely published that Shackleton made the first ascent but that’s another matter…

Getting There

Mulu National Park from near the Entrance Station.Mulu National Park with Gunung Mulu in distance rising into clouds.

Mulu National Park is located in the northern portion of Sarawak, Malasia. There are three primary methods to get to the park. Almost all visitors take an airplane to Mulu. There are regular fligths from Kota Kinabalu via Miri to the park as well as direct flights from Kuching. Most if not all flights are through Malasia Airlines. A second means of getting to the park is taking an express boat up the Barum River from Miri to Marudi. From there, one must take a second boat up the Tutoh River to the town of Long Terawan, arriving late in the day. A final boat must be hire to then go the remaining distance to Mulu. If all goes well, the trip takes 10 hours. The final means that can be used to access the park is walking the Headhunder Trail from the town of Limbang.

Gunung BenaratGunung Benarat; Mulu National Park


Trail with rope. Difficult trail not far from the summit.

The climb of Gunung Mulu is approximately 24 km from the boardwalk in the park to the summit and thus 48 km round trip. Starting elevation is approximately 50 meters. The climb is usually accomplished in 4 days and three nights but can be done in 3 days if you are fast. A one day blitz of the peak would be likely to fail, as there are lots of up, down, roots, cliffs, mud, etc. Conveniently, there are three huts along the way to spend the night, Camps 1, 3, and 4. One possibility is to go to Camp 3 day 1, Camp 4 the second day, summit and return descend to Camp 3 on day 3, and return on the final day. Another option is to go to Camp 1 on the first day, Camp 3 on the second, summit and return to Camp 3 on day 3, and return on day 4. That itinerary decreases the chances of seeing a view from the summit. It is also possible stay at the first camp on day one then go all the way up to Camp 4 on day 2 (only 8 miles but a shockingly taxing hike). The third day would then be used to reach the summit and then descend as far as possible.

Forest; Gunung Mulu

Since describing each section of the climb in detail would likely take some of the fun away from the climb, what follows is just a brief outline of the route. The beginning of the climb is on a clean, well maintained boardwalk. Even after turning off of this, the trail is good and flat although there are a few streams and rivers to cross. However, after a fairly mellow trip to camp 1, things get steep to Camp 3 (Camp 2 is a tent spot and not used). After that, once the ridge is reached there are about 5 km of no net gain in elevation but little flat ground to Camp 4. Many would consider the final portion to the summit the most engaging and perhaps the most enjoyable stretch as well. If it has rained recently there is a good chance that you might pick up some leeches low on the mountain. I got 12 of them myself although only 2 attached. It’s a good idea to spray bug repellant on your socks and lower legs to discourage these creatures, although clearly I was less that totally successful with this.

Red Tape

Dawn summit viewDawn Summit View

In order to climb Mt. Mulu, you must work with the staff of the National Park. There are red tape hurdles that must be met or the trip may not occur. You are required to have a guide. These people are from the local community and are quite knowledgeable about the surroundings. Our guide was, I believe, the great grandson of Tama Nilong. Ideally, you should have a group of at least three people to go. With two people, the trip might occur if there is a guide available but also might not. With a lone person, the chances are not strong that you will be able to carry out the ascent. Park regulations require four people so you would need to have a guide as well as two porters if you are alone. Furthermore, the arrangements must be made early enough that there are guides and porters available. I made my initial inquiries in November, was joined by two Belgians in the spring, and made the ascent in July. With three people, the cost is 650 ringgit or about $160 USD (2018) each. If there are only two people, you would need to pay for the cost of the third individual as well. One person would have to pay for all three.

When to Climb

Gunung Mulu can be climbed at any point during the year. With that said, the area receives somewhere in the vicinity of 400 inches of rain per year so expect that there will be some rain. In general, this portion of Borneo has a double monsoon with dryer weather in July - September and February through April. The months of October through January and May through June tend to be the wettest times. July through September are the driest months of the year with rain falling on less than half of the days.


Nepenthes lowii Near Gunung Mulu Summit.Nephthytis lowii
The diversity of plants is one of the wonders of Mulu. During the hike, one goes from lowland rainforest with tall, buttressed trees, up through several assemblages of plants to the mossy forests where mists swirl past many afternoons and the world around you is coated in vibrant green mosses. The upper part of the mountain holds many carnivorous Nephthytis plants, from tiny ones that are easily overlooked to Nephthytis lowii near the summit which is larger than a hand. What is particularly intriguing about lowii is that it actually lures shrews and other critters to lick from its top while perched above its reservoir of water and enzymes attempting to get the shrews to poop into the chamber whereby it is then able to break down the organic molecules for the nitrogen contained within. Needless to say, many of the organisms found on this mountain can only be seen in the high mountains of Borneo and nowhere else on Earth.


Frog; Mulu National ParkFrog
Rajah Brooke s Birdwing Butterfly, Mulu National ParkRajah Brooke's Birdwing
Many of the large creatures found in Borneo are seen more easily at parks other than Mulu. Although there are clouded leopards, gibbons, several species of monkeys, and a host of other large mammals, those at Mulu tend to be more apt to flee human contact than those seen in many other wildlife areas. With that said, low on the mountain, a night walk or careful observation during the day reveals a large number of stick bugs, centipedes, spiders, frogs, and snakes. If you enjoy seeing creepy crawlies, Mulu is a phenomenal destination. The same can be said about butterflies. Giant blue, green, black, and so many other colored butterflies flit through the trees in perplexing manner, bringing vibrant splashes of color to contrast with the perpetual green of the forest. Mulu is further renowned for its birding although it can be hard time seeing the birds through the trees.
Pit Viper; Mulu National ParkPit Viper
Spider; Mulu National ParkSpider

Other things to do in Mulu National Park

Bats leaving Deer CaveBats exiting Deer Cave

Deer Cave and Bats

Perhaps no creepy crawly is more famous than bats and there may be no better place than Mulu to see the mass exodus of millions of bats (from a record 12 species) into the evening skies on many nights from the famed Deer Cave. One warning is that the bats are not predictable. Some nights, particularly when it is raining, the bats do not appear. On other occasions they are cool but not to the degree that you are blown away and left speechless. Then there are nights where you are and for half an hour clouds of these mammals stream into the sky swirling and swaying in some rhythmic mass dance leaving you awed by the magnificence of nature. This is frequently followed by the arrival of bat hawks and a deadly series of dogfights between predator and prey as darkness slips over the forest.

The Pinnacles

Although Gunung Mulu is sandstone, the most famous areas of Mulu are made of limestone which has weathered into an elaborate network of passages, sinkholes, and in a couple places spires and pinnacles that thrust high up into the sky. The most easily reached and most aesthetic of these features is found on the slopes of neighboring Gunung Api. As is the case with Mulu, you are required to have a group of at least 3 people for this trip and you are also required to have a guide. Similarly, this is a multi day endeavor, the first being to walk 9 kilometers through beautiful, flat forest to Camp 5. A recommended additional activity is to visit Clearwater and Wind Caves which can get into their own superlatives such as Clearwater cave being over 200 kilometers long… Anyways, once at Camp 5 there are wonderful pools to swim in while simultaneously salivating over the thought of climbing the magnificent limestone cliffs facing you on Gunung Benerat. After a night at the camp (where mosquito netting is recommended) you awake early to climb 1,200 vertical meters in 2.2 km total. There is a fairly strict timeline enforced. You go the pace of your group’s slowest member, and if you haven’t reached particular places by particular cut off times, the guides will make you turn around. Anyways, near the top you enter that magical realm of mosses and carnivorous plants, climb some 17 ladders, and eventually crest a hill to see the pinnacles of Gunung Api which are quite aesthetic!

Pinnacles; Gunung ApiPinnacles; Gunung Api

Sarawak Chamber and Clearwater Connection

Arguably, the largest cave chamber in the World is Sarawak Chamber found not far from Camp 1 in Mulu National Park. Frequently, this is reached with an overnight at the camp and involves a walk through the previously mentioned leech forests, multiple stream and river crossings, and then an adventurous wade through a short slot canyon that quickly becomes a cave and up an underground river for quite some distance eventually to a steep climb up bat guano covered rocks to reach the chamber. We turned around at a point where in one direction the light of the flashlight disappeared into the void. However, we were told that it was dangerous to go into the chamber proper as there are many massive perched rocks, and thus wasn’t done without special permission. Almost everyone said that there were other so called adventure caving experiences that were better in the park, such as Clearwater Connection in Clearwater Cave. Personally, there is something intriguing about a chamber large enough to hold 18 747’s… Regardless, advanced adventure caves such as Sarawak Chamber require either a verifiable caving resume or at least one day on a so called intermediate level cave where the guide assesses your abilities.

Deer Cave; Mulu National ParkDeer Cave

Parting Thoughts

Most people spend 2 – 3 days at Mulu. I spent 10 and left very content with the wonders that I’d seen but still feeling that I could have stayed a bit longer. Most people say that the pinnacles are preferable to climbing Gunung Mulu however, in retrospect I actually liked the peak more in a way that you slog for hours up relentless trails, collapse at the end and the next day only remember how stunning the experience had been…

External Links

Gunung ApiGunung Api from near Camp 4

I used the following for information in writing this up:

Some of the history:

Costs of the trip:

The official website for the park is:

A You-Tube video showing the summit view: 

Sunset from Camp 4

Camp 4 Sunset