The discovery was made by international experts following a recent exploration of some caves in the system, the CentralHighlands province of Dak Nong, as part of the 20th international symposiumon vulcanospeleology there from November 22 to 26.
During the survey, they found some new passages about 175mlong in total, which extends the length of Cave C7 to more than 1,240m,according to the management board of the Dak Nong UNESCO Global Geopark.
Experts will return in the next few days to measure and createa 3D map of this cave.
TheKrong No volcanic cave system, about 10km long, is the largest, longest, andmost unique of its kind in Southeast Asia. It was discovered and publicised in2014.
Scientistshave also found vestiges of prehistoric humans dating 6,000 - 7000 yearsago there. These traces were announced in September 2018.
Earlier,similar traces had only been recorded in a volcanic cave system in the Republicof Korea./.

