Niah National Park is located 10km inland and about 96km south-west of Miri. The park has a size of 3,140 hectares of forest and limestone karst areas. The area was declared a National Park on 02-JAN-1975.
The Sungei Subis (Subis river) flows along the park's western border. Gunung Subis (Mount Subis), a large, almost vertical limestone massif which rises from the plain little above sea level to 397m asl covers about 60% of the area. The limestone was originally formed as a coral reef in the Lower Miocene. Later it was uplifted and modified by faulting and erosion.
There are several hundred caves within the park boundaries. The two most interesting ones are Gua Niah (Niah Great Cave) and Kain Hitam (Painted Cave). Both are of imense archaeological interest.
The park has numerous other caves, several of them are of archaeological interest.
For a visit to the caves a permit is needed. For the painted cave a special permit is needed, which must be obtained prior to the visit from the Park authorities in Kuching. Spelunking and climbing is not allowed in the park.