Macquarie Island

Made a state reserve in 1978 and a UNESCO World Heritage Site in 1997, Macquarie Island is geologically unique in being the only place on the planet where rock straight from the Earth's mantle — normally locked away beneath kilometres of oceanic crust — lies continuously exposed above sea level, thrown up by the very process of sea-floor spreading around it. It is the only known breeding place in the world of the royal penguin, an endemic subspecies whose entire world population is confined to this island, and it holds over three million penguins of other species through the breeding season.