The Great Barrier Reef is the world’s largest coral reef system located in the Coral Sea, off the coast of Queensland, Australia.

Explanation:

The Great Barrier Reef is remarkable in that it spreads from shallow estuary areas to deep oceanic waters, spanning 14 degrees of latitude. A diverse diversity of ecological groups, habitats, and species may be found within this immense area, making the Reef one of the world’s most complex natural ecosystems.