Gunung Mulu NP, Part 1: The Caves

Gunung Mulu National Park offers great jungle trekking and one of the largest cave systems in the world, making it one of Borneo’s highlights. The park can only be reached by plane (it’s a cheap 45 min flight from Miri) but it still is by far the most popular national park we‘ve been to. We intended to do the Pinnacles Route (which takes 3 days) so we decided to stay for 5 full days and booked our flights accordingly.


Mossy tree

The accommodation of the park was fully booked when we arrived (which we had expected after inquiring per email) so we stayed at the dorm of the hostel right at the park entrance. Almost everything in the area is pretty expensive compared to the coast btw, most likely because it is so remote: a single bed in the 24-bed dorm cost 35RM per night, a meal cost 10-15RM and a beer cost 8RM. Bad news was that the Pinnacles Route, which requires a guide and bookings for accommodation at Camp 5, was also fully booked for the next 5 days. So we had lots of time to explore the caves and trails around park HQ. We spent the first 2 days exploring the 4 ’show caves‘. These caves are very accessible, they have a paved walkway or plankwalk, handrails and they are lit so they can be visited by everyone. A good torch comes in handy to have a closer look at some of the stone formations but it is not required. For some reason you are still required to take a guided tour in order to visit them.

On the first day we went to Deer Cave and Lang’s Cave. A very easy 3km plankwalk leads to the caves which are close to each other but still very different. Lang’s Cave is a small and rather narrow cave with some beautiful stone formations while Deer Cave is a vast passage more similar to the Great Cave at Niah NP: it is more than 2km long and more than 150m high in places. We had walked towards the caves in heavy rain and when we stood in Deer Cave, waterfalls had formed there, dropping water more than 100m from the ceiling of the cave. I took some photos but they cannot describe what it felt like to be there.


Waterfalls in Deer Cave after heavy rain

There had been many people in the cave but when we emerged again, we were still surprised to see the large crowd of people waiting near the cave entrance for the millions of bats which leave the caves between 5 and 6 pm on most days.


Bats leaving Deer Cave in the late afternoon

On the second day we went to Wind Cave and Clearwater Cave. The guided tour includes a good boat ride from park HQ to the caves with a short stopover at a Penan settlement along the way. The mouth of Wind Cave doesn‘t seem that spectacular but further in, amazing chambers filled with stalagmites and stalactites await you. The ceiling has collapsed in a spot near the chambers and you can see the jungle high above and light beams perforate the cave.

The entrance to Clearwater Cave is only a few hundred meters and some 300 steps away. The cave is more than 100 kilometers long and the accessible area near the mouth is a rather large passage with an underground river running through it. You can have a swim in the river outside near the steps leading up to the cave entrance, but expect many people there.


Cave of the Winds

Nobody who comes to Gunung Mulu NP misses the 4 mentioned show caves I guess and their plankwalks were packed with people — sometimes our group even had to wait for minutes until other groups had left a certain area before we could proceed. You can also walk to Clearwater Cave and Cave of the Winds on a 3km paved trail (yes, almost everything near park HQ is paved or a plankwalk) and check them out alone right after the tour groups leave in their boats. You‘ll also find the river deserted then. The trail also passes through Moonmilk Cave, a narrow tunnel with great stone formations that seem to be covered in a white substance, and the cave alone is easily worth it. Bring a torch even if you already saw the caves with the guided tour and all you want is a relaxing swim in the river because they switch the cave lighting off at around 5pm and you will have to go through Moonmilk Cave again on your way back.


Lang’s Cave

We decided to sign up for two of the adventure caving tours as well. You leave the plankwalks, handrails and lights behind with a small group, hard hats, good torches and a guide on these trips. Expect to pass through some narrow passages and get muddy, it’s also very slippery almost everywhere inside the caves. Bring a good backup torch and sturdy shoes, trekking sandals are not allowed and you would most likely cut your feet horribly on the rocks in some passages if you tried to go with them.

The easy 1h Turtle Cave tour starts near the bridge in Clearwater Cave. After wading across the river and through a muddy pool followed by some climbing over sharp rocks you can see the forest outside at an opening. The route then carries on through the low passage that gave the tour its name: you don‘t have to crawl (and you shouldn‘t because there is lots of mud and up to 20cm of water on the floor) but it’s too low to walk upright, so you‘ll find yourself doing the turtle-walk. ;)


Some large creepy crawlie in Moonmilk Cave

The water gets deeper in some parts near the end, depending on the water level of the river to a certain extent I guess. This part doesn‘t seem directly connected to the river when you walk through but when the water level rises (making the tour impossible) it most likely is. When we were there we had to swim through one of the last chambers because there was a lot of water in them. It was just a few meters and I managed to do it with my backpack in one hand above my head but I wouldn‘t recommend to bring a camera or anything that would get damaged by water on this trip. You won‘t be able to take good pictures anyway unless you bring very expensive gear and even if you have a good camera with a very bright ultra wide-angle lens in a 100% waterproof bag it’s not really worth it because Turtle Cave doesn‘t really have impressive stone formations or large chambers. It’s more about having fun climbing through the mud and water and we had a blast! When we emerged from the cave we jumped into the river outside with all our clothes and shoes on to get rid of the mud. :)


Lang’s Cave

The second adventure caving trip I did was Racer Cave, an intermediate trip that took about 3h. The cave is named after the Cave Racer snakes (Orthriophis taeniurus) that tend to hang out in a narrow passage close to the cave entrance where they lie in wait for bats. The cave requires a certain degree of fitness because you have to climb some ropes up and down steep, slippery rocks inside the cave. Apart from the snakes, bats and swallows the cave is home to some impressive spiders and other creepy crawlies. Unlike Turtle Cave there is no river in Racer Cave and you won‘t get wet unless you count the sweat.