From the museum, a raised boardwalk leads 3.1km (3½ to four hours return) through swampy, old-growth rainforest to the mouth of the Great Cave, a vast cavern approximately 2km long, up to 250m across and up to 60m high. To make it back by nightfall, start your stroll by about 2pm.
As you walk, stop and stand silently every once in a while – you’ll hear lots of birds and, if you’re lucky, may hear or even see macaques, especially early in the morning or in the evening.
Just before the cave entrance, the boardwalk forks. The right fork leads to the cave, while the left fork goes to Rumah Patrick Libau , an Iban longhouse hamlet. Villagers usually sit at the junction selling cold drinks and souvenirs.
Inside the Great Cave, the trail splits to go around a massive central pillar, but both branches finish at the same point so it’s impossible to get lost if you stick to the boardwalk. The stairs and handrails are usually covered with dirt or guano, and can get very slippery in places. The rock formations are spectacular and ominous by turns, and as you slip in and out of the gloom you may find yourself thinking of Jules Verne’s Journey to the Centre of the Earth . When the sun hits certain overhead vents, the cave is penetrated by dramatic rays of other-worldly light. When you’re halfway through the dark passage known as Gan Kira (Moon Cave), try turning off your flashlight to enjoy the experience of pure, soupy blackness.
The Painted Cave is famed for its ancient drawings, in red hematite, depicting jungle animals, human figures and the souls of the dead being taken to the afterlife by boat. At research time it was closed for maintenance until further notice.
