Hanoi, April 21 -- A survey team has discovered a new cave featuring an exceptionally rare waterfall approximately 350 metres high within the Phong Nha - Ke Bang National Park in the central province of Quang Tri, according to the park's management board on April 20. Preliminary findings indicate that the cave descends vertically to a depth of around 350 metres. A stream flowing from the top to the bottom of the cavern forms a striking internal waterfall, an unusual natural phenomenon rarely observed in cave systems. Experts noted that the survey remains incomplete, with several areas yet to be explored, meaning a comprehensive assessment has not yet been made. Authorities said further detailed research and exploration will be conducted i...