It stretchs over 344,000 square kilometres and can be seen from outer space as it is the worlds biggest single structure made by living organisms. This reef structure is composed of and built by billions of tiny organisms, known as coral polyps. 

This reef supports a wide diversity of life, and was selected as a World Heritage Site1981. It is internationally recognized as one of the seven wonders of the world.A large part of the reef is protected by the Great Barrier Reef Marine Park which helps to limit the impact of human use, such as fishing and tourism.