Final answer:
The Great Barrier Reef is the largest barrier reef in the world, stretching over 2,300 kilometers off the coast of Australia.
Step-by-step explanation:
The largest barrier reef in the world is the Great Barrier Reef located off the coast of Australia. Stretching over 2,300 kilometers, it is composed of over 2,900 individual coral reefs and is home to a diverse range of marine life.
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