Northeast coast of Australia, extending up to 250 kilometres offshore along the Queensland coastline, Coral Sea, Australia
The largest living structure on earth — an intricate lacework of 2,800 individual reefs and 900 islands stretching 2,300 kilometres along the Queensland coastline, supporting 400 coral species, 1,500 fish species, six of the world's seven sea turtle species, and roughly 30 marine mammal species including dugongs. It is the only biological system visible from space with the naked eye, and by almost any ecological metric the most significant marine ecosystem on the planet. It is also, by any honest measure, a system under severe and accelerating stress.
Ancient geological formation beginning approximately 20,000 years ago; UNESCO World Heritage inscription 1981