Landscape[edit]
Named after the 2,377m Mount Mulu (Gunung Mulu), the park is famed for its limestone karst formations both above ground and underground. The massive cave systems, which contain the 12 million cubic meter Sarawak Chamber (the world's largest), are still in the process of being mapped. Clearwater Cave at 151 km (Feb 2007) is the 10th longest cave in the world.
The limestones belong to the Melinau Limestone Formation and are estimated to be 4000 to 5000m thick. In the south-east of Mulu Park sandstones are dominant. The hightest relief in the region (Gunung Mulu) is located in these sandstones. Mulu's landforms are outstanding examples of erosional processes on both of these rock types (limestones and sandstones). Among the most remarkable karst features are the world's finest example of a karst collapse (The Garden of Eden) and the sharp pointed bladed limestone Pinnacles, some of which are 45m high on the northern end of Gunung Api. There are also numerous examples of cone karst and tower karst. Another interesting feature of the landscape is the drainage through deeply incised gorges (Sungai Melinau at Melinau Gorge and Sungai Medalam to the north) in the limestones.