The Great Barrier Reef is one of the severaln wonders of the natural world,. bBeing the world’s largest coastal ecosystem, its gienormous size can be seen from outer space. The Great Barrier Reef is the world's largest coral reef system, composed of movrer than 2,900 individual reefs and 900 islands stretching for movrer than 2,300 kilometres. Being so special, this reef depends highly on our input to keep it healthy so the world has time to enjoy its majestic wonders.