An exploration team at the UNESCO World Heritage Site of Phong Nha Ke Bang Park in central Vietnam has discovered two lakes that are so "mysteriously" deep that modern equipment had not been able to measure them.
Visitors pose near Xuyen Son Ho lake at Phong Nha-Ke Bang National Park. Recent explorations have not managed to measure the lake's extraordinary depth yet.
The lakes are around 500 meters from each other in the park in Quang Nam Province. The surface of one is about 70 square meters and the other more than 300 square meters.
Their bottoms were still out of reach to modern diving tools and ropes, which could only indicate that the lakes were more than 1,500 meters deep, said a recent Tien Phong report.
Phong Nha Ke Bang Tourism Center started allowing visitors to see the lakes on Monday and is organizing a contest to name the larger one. Explorers have named the small one Xuyen Son Ho, meaning "lake that goes through mountains."
The park won UNESCO heritage recognition in 2003 thanks to explorations by the British Cave Research Association. The cave system includes Khe Ry, the world's longest cave with a stream, and the world's largest cave, Son Doong.