The caves in Phong Nha Ke Bang are one of the top Vietnam sightseeing spots. There’s a huge national park here and some of the world’s largest caves! These caverns stretch out for hundreds of kilometres and are fascinating to explore. The world’s largest cave Son Doong has sections that go up to 200 metres in height. It is also the home of the Paradise Cave which has some brilliant stalactites and stalagmites. Tour operators in Vietnam regularly organise hiking, mountain biking and various other expeditions.