Where is it? In the Coral Sea, off the coast of Queensland. It’s the world’s largest reef system, longer than the Great Wall of China, and it can even be seen from space. Little wonder it’s a World-Heritage site. Diving around the 350,000 kilometre square reef is simply incredible. You’ll spot dugongs, green turtles, dolphins, reef sharks, more than 1500 species of fish and 4000 types of mollusks, including giant clams.For those with a keen sense of adventure, scuba dive the shipwrecked Yongala, the largest and most intact historic shipwreck in Australian waters. Or head out to the Ribbon Reefs...