Costa Rica
Cocos Island is a remote volcanic island and UNESCO World Heritage-listed national park in the Eastern Tropical Pacific, famed among divers for large aggregations of hammerhead sharks.
Cocos Island National Park protects a single oceanic island together with a large surrounding marine reserve, roughly 550 km southwest of the Costa Rican mainland. Declared a national park in 1978 and inscribed as a UNESCO World Heritage Site in 1997, its marine zone was extended in 2002 to cover about 1,997 square kilometers. Its position at the first point of contact with the northern equatorial counter-current makes it a globally significant habitat for pelagic marine life, including large schools of hammerhead sharks. The site is reachable only by multi-day liveaboard dive boats.