The low-lying island has widespread rainforest and several rare species of marine turtle. Several islands are marine turtle egg laying sites. It also provides habitat to six out of the world's seven marine turtle species. It is also possible to see the first marine turtle rescue centre in Croatia. Ao () is a large marine turtle in Chinese mythology. The municipality of San Juan has a resident marine turtle or "pawikan". Leatherback turtles are the widest-ranging marine turtle species and are critically endangered. Five marine turtle species appear regularly off the west coast but do not come ashore.