The Great Cave: An Overview

The Great Cave of Niah (Gua Besar) is one of the most impressive natural chambers in the world. The West Mouth entrance alone measures approximately 250 metres wide and 60 metres high — large enough to fit several football pitches inside. The cave system extends more than 2 km in total, encompassing the main Great Cave, the Moon Cave (Gua Bulan), and the smaller side passages that lead to the Painted Cave.

The cave is a living ecosystem. Its walls and ceiling host colonies of millions of bats — including wrinkle-lipped free-tailed bats (Chaerephon plicatus) and cave nectar bats — and hundreds of thousands of swiftlets, whose nests are collected by licensed harvesters who climb bamboo poles and rattan ropes to heights of 60 m or more.

The Plank Walk

A 3.2 km wooden boardwalk winds through primary rainforest from the park headquarters to the cave entrance. The walk takes approximately 45 minutes each way through lowland mixed dipterocarp forest, with excellent birding and occasional wildlife sightings en route.

Inside the Cave

Once inside the West Mouth, the boardwalk continues through the enormous main chamber. The scale is difficult to comprehend until you're standing inside. Your eyes adjust slowly; bring a good headlamp and take time to let your vision adapt.

The cave floor is covered in guano — the accumulated droppings of millions of bats and swiftlets. It has a distinctive, pungent smell. The guano ecosystem supports an extraordinary diversity of invertebrates: cave crickets, cockroaches, centipedes, and the cave racer snake (Orthriophis taeniurus) that preys on the bats.

The Moon Cave (Gua Bulan)

Beyond the main Great Cave, the boardwalk passes through a narrower passage into the Moon Cave — a dramatic chamber where a skylight opening allows shafts of natural light to penetrate, illuminating the cave floor in spectacular fashion at certain times of day.

Safety Notes

  • Never enter the cave without a working torch
  • The boardwalk can be slippery after rain; walk carefully
  • Do not stray off the boardwalk — the cave floor is uneven and unstable
  • Respect the restricted archaeological zones; do not touch the cave walls
  • Carry enough water — the cave is humid and the walk is long