The Great Barrier Reef is renowned as "one of the Seven Natural Wonders of the World." The reef itself is a vast biological entity composed of billions of tiny coral polyps and is the only living organism visible to the naked eye from space. The Great Barrier Reef is the largest coral reef system on Earth, running along the northeastern coast of Australia, extending from the Torres Strait in the north to just south of the Tropic of Capricorn in the south, covering a distance of 2,300 kilometers. In 1981, UNESCO listed the Great Barrier Reef as a World Natural Heritage site. It is home to thousands of species of animals and is one of the most biodiverse and ecologically varied areas on the planet. The colorful coral reefs of the Great Barrier Reef are massive, complex in structure, and diverse, providing an ideal habitat for a large number of plants and animals, including over 600 species of coral, more than 100 species of jellyfish, over 3,000 species of mollusks, more than 1,600 species of fish, 133 species of sharks and rays, and over 30 species of whales and dolphins. Although the Great Barrier Reef is a paradise on Earth, it faces significant threats, including global climate change, acid rain, widespread coral bleaching, and the overpopulation of starfish. The Great Barrier Reef is famous for its unspoiled natural beauty, attracting tourists from all over the world. Due to environmental reasons, the Great Barrier Reef is declining year by year, so if you have not yet visited to witness its beauty, be sure to add it to your itinerary; make it a priority to see the Great Barrier Reef at least once in your lifetime.