A collection of colorful underwater scenes featuring marine and coral life, from clownfish and dolphins to manta rays and sharks that are all common at the Great Barrier Reef, the world's largest coral reef system. It spans over 1,400 miles long and is home to around 600 types of coral, 1,500 species of fish, 30 species of whales and dolphins, and numerous sea turtles, birds, and marine life. The GBR is another World Heritage Site designated by UNESCO in 1981 for its ecological importance. Estimated to be around 20 million years old, with current structures dating back 6,000–8,000 years. Climate change, coral bleaching, water pollution, and overfishing are threatening the GBR. It is indeed a natural wonder, critical for marine diversity and environmental health.