Tubbataha

Declared a marine natural park in 1988, Tubbataha is a coral atoll in the middle of the Sulu Sea, more than 150 km from the nearest inhabited island and with no permanent human population. Its extreme isolation — reachable only by liveaboard boats during the good-weather window between March and June — has preserved one of the best-conserved coral reefs in the world, with over 600 species of fish and 360 of coral. It has been a UNESCO World Heritage Site since 1993 and is a strict no-take zone, watched over by rangers who live for months at a stretch on a floating platform in the open ocean to prevent illegal fishing.