The Painted Cave (Kain Hitam — "black cloth" in Malay) is a separate chamber reached via a trail that passes through the Great Cave and along the cliff face on the far side. Inside, on the cave walls, are the only known prehistoric paintings in Sarawak: a series of red haematite figures depicting stylised human forms in boats — the boats of the dead, used to carry deceased souls to the afterlife in the cosmology of the people who created them. The paintings are dated to approximately 1,000 years BP on the basis of associated burial materials.
The paintings themselves are faded and require patience to see. Most are on the right-hand wall of the cave as you enter, roughly 1–2 metres above the cave floor. Bring a powerful torch and direct it at an oblique angle to the wall surface — perpendicular light washes the images out, while raking light reveals the surface topography that defines the painted lines. The boat-of-the-dead motif repeats across the wall: elongated vessels with upswept prows, human figures with raised arms, and what appear to be paddles. Some scholars interpret the figures as dancers; others see them as deceased in repose.
Associated with the paintings were wooden coffins in boat form (perahu) and burial offerings including glass beads, iron tools, and ceramic sherds indicating trade contacts with China. These materials date from approximately 500–1,200 CE. The people who made the paintings are believed to be ancestors of the Penan or related nomadic hunter-gatherer groups of interior Borneo — though the paintings show no stylistic parallels with known contemporary Penan visual culture, making attribution uncertain.
The Painted Cave is also where some of the most significant archaeological stratigraphic layers were first recorded during Tom Harrisson's 1950s excavations. The organic-rich guano floor preserved materials over an exceptional time span. The cave is damp, the paintings are fragile, and touching the wall is strictly prohibited. A viewing platform keeps visitors at an appropriate distance. The Painted Cave is the furthest point on the boardwalk trail from the park entrance — allow 4–5 hours for the full return journey.