The Clearwater Cave System (Malay: Gua Air Jernih) in Gunung Mulu National Park, Sarawak, Malaysia is believed to be the largest interconnected cave system in the world by volume and the 8th longest cave in the world at 222 km (138 mi) (2017). The system lies mainly under the western margins of Gunung Api between the Melinau Gorge and Cave of the Winds.
The first exploration by speleologists was during the 1977/78 Royal Geographical Society Mulu Sarawak Expedition when 15 miles of the cave passage were surveyed. Many expeditions by the Mulu Caves Project have increased the explored length and will continue to do so for the foreseeable future.
- Eavis, Rob (April–May 2016). "What a Rollercoaster". Descent (249): 24–29.
- Brown, Mark (June–July 2017). "Mulu Successes Continue". Descent (256): 36.
- Mulu Caves, Brook and Waltham (1979), Royal Geographical Society
- Caves of Mulu '80, (1981), Eavis, Royal Geographical Society
- Caves of Mulu '84, (1985), Eavis, British Cave Research Association
- Mulu Caves '88 and '89 Expeditions, (1989), Kirby, Mulu Caves Project
- Mulu Caves '91 (1991), Kirby, Mulu Caves Project