I always seem to end up at aquariums when I'm in a new city, so I wasn't surprised when I got tempted to stop by Sydney's. This fair sized watery land has lots of Australia's sea life: sharks, stingrays, seahorses and more. The price is $38, a bit much...I found out later though if you book online it is only $26. There are also plenty of deals to combine tickets to other attractions, saving you a bit of money. I did the 2 attraction ticket (Aquarium and the Sydney Eye) for a total of $60.
My favorite animals were the platypus and the sea dragons as these aren't ones I see at most other aquariums.