Great Barrier Reef

The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres (1,400 mi) over an area of approximately 344,400 square kilometres (133,000 mi2). The reef is located in the Coral Sea, off the coast of Queensland, Australia. It is separated from the coast by a channel 160 kilometres (100 mi) wide in places... (Wikipedia)