Tien cave is located amidst large mountains and forests in Cao Quang commune, Tuyen Hoa district. With a total length of nearly 3km and depth of about 100m, it is the largest cave among the Tu Lan system.

In the rainy season, water from all nearby rivers flows into Tien cave and forms an underground river inside the cave. The receding water creates some natural lakes and layers of multi-shaped stalactites like terraced fields.(Photo: VNP/VNA)

A turquoise lake outside Tien cave. (Photo: VNP/VNA)

The flora inside the cave is very diverse with varieties of mushrooms and moss. The stalactites that have long been formed have a green coverage of moss.(Photo :VNP/VNA)

Discovering Mat Ngoc lake before entering Tien cave. (Photo:VNP/VNA)

Layers of stalactites like terraced fields.(Photo: VNP/VNA)

The spiral ceiling of Tien cave (Photo: VNP/VNA)

Source: https://en.vietnamplus.vn/the-fanciful-tien-cave/189909.vnp