The world's largest coral reef system is the Great Barrier Reef, located off the northeastern coast of Australia. Spanning over 344,000 square kilometers, it is home to an extraordinary diversity of marine life, including thousands of species of fish, corals, and other sea creatures. The Great Barrier Reef is a UNESCO World Heritage site and a significant natural wonder. While it supports extensive biodiversity and tourism, it faces threats from climate change, pollution, and coral bleaching. Conservation efforts are ongoing to protect this unique ecosystem, which is vital for the health of the oceans.