Brisbane Ranges NP is a national park West of Melbourne, Australia. Its size is a few tens of square kilometers and the forest is reasonibly dense. At the south-east part of Brisbane Ranges NP Anakie Gorge is located. From that location several walking tracks can be followed. Take a walk in the afternoon and you will have the chance of seeing a lot of wallabies, and may be an echidna. But of course spotting the wild koalas is best. There is quite a chance you see some koalas in this particular part of the NP. If you do happen to see no animals, the track is extremely nice situated and very much worth a visit!
In addition to the Anakie Gorge, you can also drive through the NP (north-south road is concrete) and try to spot koalas (not the driver!). The trees in the Anakie Gorge are not very high and therefore spotting a koala is not too difficult. It is possible to park the car along the road and take a walk on one of the many paths in the area. There are several non-concrete roads in the area that can still be used with only two wheel vehicles. This way you can explore quite a large area and go far a walk whenever you like to.
Click here to find Anakie Gorge on a map of Victoria

Click on a picture to enlarge.