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Created page with "== Introduction == An atoll is a ring-shaped coral reef, island, or series of islets. An atoll surrounds a body of water called a lagoon. Sometimes, atolls and lagoons protect a central island. Channels for exchange of water with the open sea may exist in the atoll ring. thumb|center|Aerial view of a circular atoll with a turquoise lagoon in the center.|class=only_on_mobile Image:Detail-35936.jpg|thumb|center|Aerial view of a cir..."
