"Visible from space, the Great Barrier Reef is the largest living structure on our planet. Stretching just over 1200 miles in length and made up of 3000 individual reef systems and hundreds of islands, Australia's Great Barrier Reef is breathtakingly beautiful. Given world heritage status in 1981, it is one of the wonders of the natural world. This programs offers a definitive guide to the secrets of the reef - how it was created, how it works, the...