A group of Vietnamese and Japanese scientists have announced the discovery of the first volcanic cave system in Viet Nam, one part of which is considered the longest such feature in Southeast Asia, according to the General Department of Geology and Minerals of Viet Nam.

The discovery was made in Krong No District in the Central Highlands province of Dak Nong by experts from the general department and the Japan Caving Association (JCA) after seven years of research, Nguyen Van Thuan, head of the department, told Tuoi Tre (Youth) newspaper in an interview published on Wednesday. 

In 2007, scientists from the general department detected some volcanic caves in the district and JCA experts have since joined their counterparts in further explorations, Thuan said.

A volcanic cave in the Dray Sap area in Krong No District, Dak Nong Province.

The system, which is a unique natural heritage of the volcanic eruption process that took place millions of years ago, is the first to have been discovered in Viet Nam.

It includes 12 volcanic caves, three of which have been measured in detail, Thuan said.

One of the three is 1,055 meters long and the Japanese scientists said it is the longest volcanic cave in Southeast Asia, he said, adding that some parts of this cave cover thousands of square meters.  

Compared with limestone caves, like those in Phong Nha-Ke Bang – a world natural heritage site in north-central Viet Nam – volcanic caves are rarer and different in structure, the Vietnamese expert said.

Researchers have yet to conclude whether people have ever lived in the volcanic caves, as they have not found any traces of human habitation, Thuan said.
However, the explorers confirmed that some animal species, including snakes, are living in the cave system, he said.

The discovery will be of great significance to international geological and archeological studies, as very few places in the world have such a system of volcanic caves and craters like that in Krong No, the expert added.
The system will also give a boost to the province's tourism development, Thuan said.

He also said it may take a long time for the joint research group, now consisting of 30 Vietnamese and Japanese scientists, to fully measure the remaining nine caves.

That is because further research will be dependent on the group’s financial ability, Thuan said.

Local researchers are supported by the state budget in paying expenditures incurred during the study, while their Japanese counterparts have engaged in the work at their personal expense, he explained.

“Therefore, it may take a few years for the group to have enough money for their work on the nine caves,” Thuan said.

In order to boost the progress of the research, the provincial authorities have formulated a plan to call for private investments, he added.

“When we have enough data on all 12 caves, we will officially declare the system to the world and devise a proposal to set up a global volcanic geological park at the location, similar to the current limestone geological park in the northern province of Ha Giang,” the expert said.