The largest coral reef in the world is the **Great Barrier Reef**, located off the coast of Queensland, Australia. Stretching over 2,300 kilometers (1,430 miles), this UNESCO World Heritage site comprises over 2,900 individual reefs and 900 islands. The Great Barrier Reef supports an immense diversity of marine life, including thousands of species of fish, invertebrates, and coral types. It is a vital ecological system and a popular destination for tourism and research. However, the reef faces significant threats from climate change, pollution, and overfishing, prompting ongoing conservation efforts to protect and preserve this natural wonder for future generations.