<p><br> Hordes of divers and other tourists descend on the Great Barrier Reef each year, but with modest environmental impact thanks to strict regulations. A much greater threat is climate change—sea-temperature rise, acidification, and more intense events such as cyclones are putting the reef at risk.</p>

Reef Rider


Hordes of divers and other tourists descend on the Great Barrier Reef each year, but with modest environmental impact thanks to strict regulations. A much greater threat is climate change—sea-temperature rise, acidification, and more intense events such as cyclones are putting the reef at risk.

Photograph by Pete Atkinson, Getty Images

World Heritage Site Pictures: Great Barrier Reef

The largest living thing on the planet, Australia's Great Barrier Reef serves up a feast of natural wonders as it stretches for more than 1,250 miles along Australia's northeast coast.

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