The Great Barrier Reef is the world's largest coral reef system, composed of roughly 3,000 individual reefs and 900 islands, that stretch for 2,600 kilometres (1,616 mi) covering an area of approximately 344,400 km².  The reef is located in the Coral Sea, off the coast of Queensland in northeast Australia. A large part of the reef is protected by the Great Barrier Reef Marine Park.

The Great Barrier Reef can be seen from outer space and is sometimes referred to as the single largest organism in the world. In reality, it is made up of many millions of tiny organisms, known as coral polyps. The Great Barrier Reef was also selected as a World Heritage Site in 1981.  CNN has labelled it one of the seven natural wonders of the world.  The Queensland National Trust has named it a state icon of Queensland.