Niah National Park, Archaeological site in Sarawak, Malaysia.

Niah National Park is a 3,138-hectare reserve of limestone hills and forest in Miri Division, Sarawak. Its Great Cave opens at the West Mouth, a 150 m wide and 75 m high gap in Gunung Subis, with a sloping earth floor crossed by wooden staircases and walkways. The park has five other openings, including Lubang Tulang and Gan Kira.

Alfred Russel Wallace discussed the caves with Robert Coulson in 1864, and Alfred Hart Everett later surveyed 32 caves in Sarawak. In 1954 Tom Harrisson spent two weeks at Niah and found evidence of long occupation; in February 1958 Barbara Harrisson's team unearthed the Deep Skull in the Hell Trench, 101 to 110 inches below the surface. The park was gazetted in 1974 and became a UNESCO World Heritage Site on 27 July 2024.

The Painted Cave, a small limestone block about 150 metres from the Great Cave's south-eastern tip, holds rock paintings dated to around 1,200 years ago. Visitors reach it by the park's plank walkways; the red figures are the only prehistoric art in the park.

The park is reachable from Miri by taxi or bus; visitors must cross the Niah River by boat to reach the caves. Exploration happens along secure walkways, and it is wise to wear comfortable shoes and watch your footing since the ground can be uneven.

Every stretch of ceiling where swiftlets roost is privately owned, and only the owner may collect the nests, which are harvested twice a year. The Painted Cave, about 150 m from the Great Cave, holds rock paintings dated to roughly 1,200 years ago.