Inside a newly discovered cave. VNA/VNS Photo

The surveyed caves have a length ranging from 30 m to 572 m each.

The four longest caves include Va cave (516 m), 12/2 Dry cave (404 m) in Phong Nha-Ke Bang National Park, Vuc Hung cave (430 m) in Thuong Trach commune, buffer zone of Phong Nha-Ke Bang National Park, and Ong Dau cave (572 m) in Lam Hoa commune, Tuyen Hoa district.

Pham Hong Thai, Director of the Park Management Board, said that in-depth surveys and studies are needed to clarify the value and make accurate judgments in preserving and sustainably exploiting landscapes and caves.