Thien Duong cave is likened as the “underground palace”or Paradise for breathtaking beauty of stalagmites & stalactites – a magical wonder of the world. The cave is 31km in length – the longest grotto in Asias but you can only get access to the part of it on a well-designed wooden path to contemplate the great beauty of unique formations of stalagmites & stalactites. The grotto nestles deep in the World Natural Heritage – the National Park Phong Nha – Ke Bang.After 500 steps trekking to the cave entrance, you are like in a cool Paradise created by the nature mother- dating back from 350 to 400 million years ago.