Krong No volcanic cave is a volcanic cave system in Krong No district, Dak Nong province, Vietnam. This is a 25 km long volcanic cave system in basalt, stretching from the crater of Buôn Choar volcano along the length of the Serepok River to the Dray Sap waterfall area. The cave sets a record for its scale, length and uniqueness in Southeast Asia, and was discovered by scientists from the Vietnam Geological Museum (General Department of Geology and Minerals) and Japanese scientists in 2014 after 7 years of research.