Great Barrier Reef is the world's largest coral reef system stretching for over 2300 kilometres. Great Barrier Reef is the only living thing on Earth that can be seen from space. This immense and complex ecosystem comprises more than 3000 individual reef systems, coral cays, and hundreds of islands, big and small, with sparkling white sandy beaches. There is a real underwater living world composed of hundreds types of soft and hard coral, creating a colorful and mesmerizing home to endless numbers of species of tropical fish, sea stars, turtles, and dolphins. A visitor can enjoy many experiences including snorkelling, scuba diving, aircraft tours, bare boats, glass-bottomed boat viewing, educational trips, cruise ship tours. A large part of the reef is protected by the Great Barrier Reef Marine Park, which helps to limit the impact of human use, such as fishing and tourism.