This is situated in Yatagampitiya remote village (5 Kmtrs. away from Bulathsinhala) in the Kalutara District. This cavern is supposed to be the largest natural rock in Asia and this is also known to be the most ancient pre-historic human settlement in Asia. It is believed that this cavern was abode by prehistoric Cavern men some 37000 years ago. This cavern is supposed to be the largest natural rock in Asia. The cave lies 400 feet above sea level. There are some natural tunnels running inside the cavern but at present those are blocked.
There is a deep pit dug out by the Archaeological Department for an excavation. Within this pit have been found five human skulls which were identified as 37,000 years old, Some weapons made of stone and animal bones.
The name of the cave is derived from the name of the Chinese buddhist priest " Fa- Hsien" who visited the cave in the 5th century. At present there is a large sleeping Buddah Statue with in the cavern.
People who visit here can bath by using Kalu Ganga (River) which is flowing near to the Pahiyangala cavern.