HANOI, Dec. 13 (Xinhua) -- Phong Nha Ke Bang National Park, a UNESCO world heritage site in Vietnam's central Quang Binh province, home to the world's largest cave, has recently spotted 58 caves and grottos in its core and buffer zones.
Among the 58 caves, some are big and valuable, the national park announced on Wednesday, noting that many caves might have been used by Vietnamese soldiers in the wartime because the park's staff have found some objects such as cartridge cases there.
The park's staff will continue to search for hard-to-access caves, and then transfer the list of newly-spotted caves and grottos to British experts for further surveying.
In 2009 in Phong Nha Ke Bang, Son Doong Cave was discovered, becoming the world's largest cave with over five km in length, 200m in height and 150m in width.
Even before the discovery, Phong Nha Ke Bang held several world cave records, including the longest underground river as well as the largest combined caverns and passageways.