Both the Indian Ocean and the Pacific Ocean touch Australia. The Pacific Ocean is mostly to the east and south, and the Indian Ocean is mostly to the west.
More specifically, Australia is surrounded by a number of seas. The Arfura Sea is to the north, while the Timor Sea is to the northwest. The Coral Sea is east, and the Tasman Sea is southeast.
The Coral Sea contains the famous Great Barrier Reef, which is the largest living structure on Earth, according to the Great Barrier Reef Marine Park Authority. It is known for its colorful reefs and diverse wildlife, including turtles, crocodiles, jellyfish, sharks, mollusks and dolphins. The reef became a protected park in 1975.