The characters on the walls of Bi Ky grotto in Phong Nha cave in Phong Nha-Ke Bang National Park were drawn by the ethnic Cham people 1,000 years ago, the Sai Gon Giai phong (Liberated Saigon) newspaper reported.

Prof. Dr. Arlo Griffiths, a member of the research team from the French School of Asian Studies, said the characters were written in the early 11 th century, adding that the group of scientists are currently conducting further research on the drawings.

Le Chieu Nguyen, Deputy Director of the Phong Nha-Ke Bang Tourism Centre, said determining the age of the characters is important since it demonstrated the presence of the ethnic Cham people in the area, adding to the cave system’s cultural value.

The experts pledged to share their research findings for further use in cultural preservation and tourism, he noted.

On July 3, the national park in central Quang Binh province was recognised as a World Natural Heritage Site by UNESCO for the second time since 2003, based on its geological and geomorphological criteria.

In 2012, Prime Minister Nguyen Tan Dung issued the decision to expand the National Park from 85,754ha to 123,326ha.-VNA