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.
Photograph by Pete Atkinson, Getty Images
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 Reinhard Dirscherl, Corbis Images
For sheer diversity, the Great Barrier Reef is hard to beat. It hosts 5,000 types of mollusks, 1,800 species of fish, 125 kinds of sharks, and innumerable miniature organisms. But the most riveting sight of all—and the main reason for World Heritage status—is the vast expanse of coral.
Photograph by Norbert Probst, Corbis Images
The countless nooks and niches of the Great Barrier Reef promote enormous biodiversity and provide a home for critters like the red lionfish, beautiful but venomous.
Photograph by Huber/Sime, eStock Photo
The turquoise waters of Hill Inlet spill off Whitsunday Island into the Coral Sea. Whitsunday and its sister islands are a stopping-off point for reef visitors.
Photograph by Arterra Picture Library, Alamy
Although the name suggests a continuous strip, the Great Barrier Reef is actually a commonwealth of at least 2,800 reefs. Only some are true barrier reefs. Others, like Heart Reef, are circular or crescent reefs.
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