Raja Ampat
Off the northwest tip of West Papua, Raja Ampat holds, by most measures, the richest marine biodiversity found anywhere on the planet. Diving here means drifting past reefs thick with soft coral, and the number of fish species recorded at a single site can run into the hundreds. It takes real effort to reach, several flights and a boat transfer at minimum, but for serious divers it is often described as the best diving left anywhere in the world.