Gunung Mulu is Sarawak’s largest national park (544 sq km), and also Malaysia’s first World Heritage Area, a status it was awarded in 2000. It is most famous for its limestone cave systems, including the world’s largest natural chamber (the Sarawak Chamber), the world’s largest cave passage (Deer Cave) and the longest cave in Southeast Asia (Clearwater Cave).
The park’s main attractions are the four show caves, all readily accessible by wooden walkways and paths. Other fascinating sights and activities include; a bat observatory; a rainforest canopy skywalk; adventure caving trips to some of Mulu’s less accessible caves; the challenging Mulu Summit climb, the spectacular Pinnacles trail, and the historic Headhunter’s trail through remote rainforest scenery.
Situated 100 km from the coast, the park is dominated by three mountains - Gunung Mulu (2,376m), Gunung Api (1,750m), and the as yet unconquered Gunung Benarat (1,585m). Gunung Mulu is sandstone, whilst Gunung Api and Gunung Benarat are formed from limestone and therefore have different geographical features.
The summit of Gunung Mulu is covered by moss forests and stunted montane vegetation, whilst razor-sharp limestone pinnacles, some as high as 50 metres, are found on the upper slopes of Gunung Api. The park’s forest ecosystems include peatswamp, heath, mixed dipterocarp, moss forest and montane vegetation – home to thousands of species of ferns, fungi, mosses and flowering plants, including 170 species of orchid and 10 species of pitcher plants, an impressive variety of mammals, birds (including 8 species of hornbill), frogs, fish and insects. Mulu’s wildlife is often heard but not seen, but visitors are almost certain to encounter bats, swiftlets, cave dwelling insects, snakes, lizards, tree frogs and an abundance of beautiful butterflies.
Upon arrival visitors must register at the park office and pay the park entrance fees. Guides and boats can also be booked here. A short walk from the Park Office is the main accommodation building, which also offers a canteen, a small shop selling souvenirs and basic essentials, and an interesting and well designed Information Centre.
Visitors may not enter any of the caves or the Mulu Canopy Skywalk without a Park Guide. For most trails, including the Mulu Summit climb, the Pinnacles trail and the Headhunter’s trail, a Park Guide is also mandatory. Bookings and payment of fees can be made ay the park office. If you require a Park Guide you need to book the day before. During peak season, guides for popular activities such as the Pinnacles trail may be fully booked weeks in advance.
Visiting the Show Caves
Note: Visitors may only visit the show caves at fixed times, and only when accompanied by a park guide, in order to minimize human impact on the delicate rock formations and cave ecosystems. A flashlight, sturdy non-slip shoes, rainwear and insect repellent 37 are essential, and a hat can be useful to protect from dripping bat guano. The use of tripods and monopods are strictly forbidden, as are smoking and littering.
Wind and Clearwater Caves
Meet the Park Guide at the Wind Cave (either 09.45 or 10.30, booking required), travelling by longboat along the Melinau and Clearwater Rivers. If the water is low, you may have to get out and help to push the boat. The boats usually make a short stop at the Batu Bungan Penan Settlement, where Penan women operate a small craft market (closed Sundays) offering a wide selection of superb handicrafts, including rattan mats, baskets, woodcarvings, jewellery and musical instruments. Alternatively there is a 3 km trail from the Park HQ passing by the Moonmilk Cave, so named for the soft white cheese-like sediments found in the cave.
The entrance to the Wind Cave is situated above an ancient Berawan burial site. Inside, cool breezes can be felt at narrow parts of the cave, and there is a spectacular chasm caused by a catastrophic roof collapse to the left of the walkway. Further into the cave is a circular walkway leading through the King’s Room; a chamber with a fine collection of calcite stalagmite (upward growing) and stalactite (downward growing) formations. The formations are carefully lit to bring out their bizarre and dramatic appearance.
From the Wind Cave, a short walk along the river leads to the Clearwater Cave. Formed by an underground river which emerges near the cave mouth, it is Southeast Asia’s longest cave passage at over 170km. From the river, 200 steps lead to the cave mouth, which has some superb dripping stalactites and two species of bizarre oneleaved plants (Monophyllae pendula and M. glauca). Inside the cave entrance are strange spike-like formations formed by bacterial action, all facing towards the cave entrance. As the bacteria are dependent on sunlight, the formations become smaller and more delicate further into the cave.
At the end of the walkway is a bridge across the subterranean river, where visitors can clearly see how the cave was sculpted by the force of rushing water. A skylight formed by a roof collapse and a great vault formed by a floor collapse (in the adjacent Lady Cave) are amongst the other unusual features of the cave system. There is an excellent swimming area at the cave entrance, with changing and picnic facilities. Most visitors stop here for a lunch and a relaxing swim.
The Turtle Cave
The Turtle Cave is an alternative exit route from the Clearwater Cave. Visitors are led into the subterranean blackness of the underground river, clambering over sharp rocks and swimming with the river current to emerge into a crystal clear pool. A waterproof flashlight and sturdy shoes are essential, and this add-on tour must be booked in advance.
Deer and Langs Caves
Guided tours leave the Park HQ daily at 1.30 and 2.30 pm. A 3-km wooden walkway passes through peat swamp, alluvial flats and limestone outcrops before reaching the Deer Cave, which at 120 metres high and 100 metres wide is the world’s largest discovered cave passage. The cave is home to the world’s largest known bat colony comprising several million bats from 12 different species, and their droppings and remains have created a thriving and complex ecosystem on the cave floor. The billions of invertebrates include a unique species of luminous centipede, and cave racer snakes and pythons can occasionally be seen. The huge cave passage was formed by an ancient river that carved the spectacular scalloped walls and left a number of fascinating rock formations; at one point it is possible to see a remarkably lifelike profile of Abraham Lincoln outlined at the cave entrance.