Great Barrier Reef

Created in 1975 after an intense campaign by conservation organisations — led by the poet and activist Judith Wright — that succeeded in stopping plans for oil drilling and mining within the reef, it is the largest structure built by living organisms on the planet, visible even from space. It has been a UNESCO World Heritage Site since 1981. Made up of more than 2,900 individual reefs and 900 islands along 2,300 km of coast, it holds roughly a third of all the soft coral species known in the world. It has suffered several severe episodes of mass coral bleaching over the past two decades as ocean temperatures have risen with climate change, though recent studies by the Australian Institute of Marine Science have also documented marked phases of recovery, thanks to the fast growth of Acropora coral after the worst episodes.