Thien Duong-the longest cave in Vietnam

Thien Duong cave in Phong Nha-Ke Bang national park in the central province of Quang Binh has been considered as the longest in the world.

From a 5 kilometres stretch of the cave discovered in 2005, the British Cave Research Association continued in 2010 that it was 31.4 kilometres long.

The cave has been open to the public since the end of last year and visitors have to climb 524 steps to reach the cave.

Inside there is a 1 kilometres long and 1m wide wooden bridge, the longest of its kind ever seen in Vietnam.