Karst islands, reefs, Raja Ampat, West Papua, Indonesia

Above the reefs

Looming just off Bird's Head Peninsula, the Raja Ampat island chain sits smack in the middle of the Coral Triangle—a vast region astride the Pacific and Indian oceans that includes the world's most biodiverse marine zones. Of all the coral species that build reefs, more than three-quarters are found in pockets of the Triangle, though it covers less than 2% of the world ocean's total area. Raja Ampat is renowned as one of the top hotspots for seeing aquatic life, particularly as a place where divers can swim with both reef-dwelling and oceangoing manta rays—two populations seldom seen together.