Discover the Great Barrier Reef

The reef runs along the edge of Australia's continental shelf in the Coral Sea, separated from the Queensland coast by a lagoon that varies from a few kilometers wide in the north to more than 200 kilometers wide near its southern end.

Its nearly 3,000 individual reefs and around 900 islands range from small sand cays to larger continental islands like those in the Whitsundays, giving the system a genuinely varied landscape rather than one continuous formation.

The reef's northern sections, closer to the equator, tend to have healthier coral cover than areas further south, where warmer water temperatures and agricultural runoff from the mainland have caused more visible coral bleaching and decline in recent decades.