One of the world's best aquariums features impressive underwater walkways through two enormous tanks - one swimming with fish found in Sydney Harbour, and the other full of giant rays and three-metre-long Grey Nurse Sharks. A giant clear plexiglass room suspended inside a pool offers views of the underwater antics of rescued seals, while the magnificent Great Barrier Reef section has thousands of colourful fish and coral outcrops. Also on display are salt water crocodiles, fairy penguins, and other sea creatures