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It begins about 10,000 years ago, toward the end of the Ice Age.
A group of tiny organisms called coral polyps dies. The animals, which had attached themselves to the ocean floor near the shoreline, leave behind their hard, limestone skeletons. These, in turn, form a base for the next generation of polyps. And on and on. Today — billions of polyps later — that limestone floor has grown to support the world’s largest structure made by living organisms.
You may have heard of it. It is one of the seven natural wonders of the world. Its name — the Great Barrier Reef.
