The largest living structure on Earth is the Great Barrier Reef of northeastern Australia, Queensland. Located in the 25-30° warm Coral Sea waters it has a length of 2570 km and is even visible from space. In contrast to the submerged atolls and the fringing reefs aligning the coasts, a Barrier-Reef is separated from the mainland by a lagoon. The reef consists of numerous coral islands. The most famous is Hardy Reef with its heart-shaped structure. It is located approximately 100 km off the coast of Australia.
Canon 20D, Canon EF-L 24-105mm, f/4, 1/500sec, ISO 100, aerial photography