It's often said that scientists believe the earth's crust formed right about where the Bunaken Marine Park is. How they know that, or how precise the theory, is hard to tell, but the dramatic volcanic landscapes have created some spectacular diving.

Not far from North Sulawesi's capital, Manado, Bunaken and her neighbouring islands appear to be part of a submerged mountain range that was flooded by the sea.

Along with the islands just north of the park, the steep walls drop from just below the surface to unattainable depths. There's a huge variety of soft and hard corals and masses of reef fish - fusiliers, butterflies, angels, sweetlips, cardinals and damsel fish - while turtles and sharks make occasional appearances.