Gunung Mulu National Park

The Gunung Mulu National Park is a national park in Miri Division, Sarawak, Malaysia, is a UNESCO World Heritage Site that encompasses caves and karst formations in a mountainous equatorial rainforest setting. The park is famous for its caves and the expeditions that have been mounted to explore them and their surrounding rainforest, most notably the Royal Geographical Society Expedition of 1977–1978, which saw over 100 scientists in the field for 15 months. This initiated a series of over 20 expeditions now drawn together as the Mulu Caves Project . 

The national park is named after Mount Mulu, the second highest mountain in Sarawak. 

Gunung Mulu National Park is famous for its limestone karst formations. Features include enormous caves, vast cave networks, rock pinnacles, cliffs and gorges. Mount Mulu is a sandstone mountain rising to 2,376 m (7,795 ft). 

Gunung Mulu National Park has the largest known natural chamber or room – Sarawak Chamber, found in Gua Nasib Bagus. It is 700 m (2,300 ft)) long, 396 m (1,299 ft) wide and at least 70 m (230 ft) high. It has been said that the chamber is so big that it could accommodate about 40 Boeing 747s, without overlapping their wings. The nearby Deer Cave is one of the largest single cave passages in the world. 

Other notable caves in this area are Benarat Cavern, Cave of the Winds, and Clearwater Cave, the 8th longest cave in the world (May 2014) and believed to be the largest cave in the world by volume at 30,347,540 m3 (1.071713×109 cu ft). 

Mulu's limestones belong to the Melinau Formation and their age is between 17 and 40 million years (Late Eocene to Early Miocene). 

Stratigraphically below the limestones, and forming the highest peaks in the south east sector of the Park including Gunung Mulu, lies the Mulu Formation (shales and sandstones). The age of these rocks is between 40 and 90 million years (Late Cretaceous to Late Eocene). 

Eight species of hornbill have been spotted in Mulu including the rhinoceros hornbill (Buceros rhinoceros) which is featured on Sarawak's state emblem, the white-crowned hornbill (Berenicornis/Aceros comatus) and the helmeted hornbill (Buceros vigil) with its large solid casque (an enlargement on the bill). 

Twenty seven species of bat have been recorded in Mulu. Deer Cave in the southern limestone hills of the park is home to an enormous colony of Wrinkle-lipped bats (Tadarida plicata). The bats exit the cave almost every evening in search of food in a spectacular exodus. A huge mound of guano in the cave is evidence of the size of the bat colony that roosts in the cave's high ceilings. 

Mulu's mammals also include the bearded pig Sus barbatus, the moonrat Echinosorex gymnurus, shrews, the Bornean tarsier Tarsius bancanus, the long-tailed macaque Macaca fascicularis, gibbons, squirrels, and three types of deer including the small barking deer and mouse deer. The small Malaysian sun bear Helarctos malayanus, which is the only bear known in South-East Asia, has also been identified in Gunung Mulu National Park. 

A number of amphibians are only known from the Gunung Mulu National Park, including squat frog Calluella flava  and stream toad Ansonia torrentis. 

Gunung Mulu National Park contains a large number of plant species, including flowering plants, trees, and fungi. Geology, soil types and topography have given rise to a rich tapestry of plant zones and types. On Gunung Mulu itself these include lowland mixed dipterocarp forest, lower montane forest, mossy or upper montane forest and summit zone vegetation on the highest peaks. On the limestones there is lowland limestone forest as well as lower and upper montane limestone forest. Other plant communities dominate the alluvial plains, including kerangas (tropical heath forest) and peatswamp forest.