If you plan to stay within the city, Wild Life Sydney is the best place where you can catch all the marsupials you'd find in Australia. Also, you get to pet the little kangaroos and feed eucalyptus leaves to the koalas.
Australia’s native species are on display in natural settings at this relatively new wildlife center, including kangaroo and wallaby exhibits, and an open koala enclosure. You can see the world’s deadliest snake, one of the world’s largest crocodiles (ask the zookeeper how they moved him into his “bachelor pad”!), and a whole entourage of colorful characters. For a truly memorable experience, splurge a little on the weekend-only Koala Breakfast – you’ll get a private tour of the park before the crowds, a fantastic buffet breakfast, and a picture with the koalas.