An unusual stalactite whose colours keep changing has been discovered by explorers in the Phong Nha-Ke Bang Natural Heritage site in Quang Binh Province.

It is 1.5km inside Huyen Khong Cave, around 2m wide and over 5m high, and its colours change constantly under lights.

Le Thanh Loi, director of the Phong Nha Culture and Ecological Tourist Centre, said it is the first time that such a stalactite has been found.-VNS