Australia's Great Barrier Reef

S1, E3: The Great Barrier Reef is one of the world's natural wonders, drawing travelers to its shimmering, multicolored coral reefs, teeming with fascinating marine life. Relive the dramatic discovery of the Reef in 1768, and learn about its complex, layered ecosystem, the largest structure ever built by living organisms. Witness the huge diversity of its wildlife and assess man-made dangers to the Reef.