Stretching 2,300 kilometres (1,430 miles) along the northeastern coast of Australia, the Great Barrier Reef is the largest living structure ever built by any organism on Earth. Comprising more than 3,000 individual reefs and 900 islands, this extraordinary natural marvel is the only single living organism visible from the vacuum of space — a testament to the sheer, incomprehensible scale of life working in concert over millions of years.

Formed by countless generations of coral polyps secreting calcium carbonate skeletons, the reef has grown and evolved over approximately 20,000 years into an ecosystem of breathtaking complexity. It supports an astonishing diversity of life: over 1,500 species of fish, 4,000 types of mollusc, 240 species of bird, and six of the world’s seven species of sea turtle. The World Records Authority recognises the Great Barrier Reef not merely as a natural wonder, but as the single largest animal structure ever to exist on this planet — a living record in every sense of the word.