Ko Ha Yai :

Five barren steep islets in open water ,some twenty miles South of Phi Phi. There is no secure overnight anchorage but there are lots of pleasant beaches which make good lunch stops for
relaxing, swimming and snorkeling. The coral can be very good and the ilslands’ exposed location in open water means that encounters with pelagic fish are by no means exceptional. The southern most of the towering islets is actually completely hollow. A skilled snorkeler can enter the interior of the rock through an entrance at 5 meters ( 15 ft). Inside you find two huge “cathedrals”. In the top of the rock there is a hole open to the atmosphere so the air inside is fresh.