Members of the Vietnam Archaeological Institute and the Bac CanMuseum have been excavating the area for possible prehistoric remainssince June.
Numerous artefacts, dating from 20,000BC to10,000BC, have been found in Tham Hau, Tham Coc Nghiu and Tham Myavillages in the Nang River valley.
Trinh Nang Chung,from the Vietnam Archaeology Institute, said Stone Age people inhabitedthe area for many thousands of years and were responsible for what hasbecome known as the Hoa Binh culture (10,000 BC). /.