Gleynlyon Caves and Viator Hill Caves (collectively referred to as Texas Caves after a nearby town) are the only two major limestone cave areas in south-eastern Queensland. Unfortunately, they were drowned by Glenlyon Dam in the mid 1970s, in an act of sheer environmental vandalism.
To get there, you need to drive for a long time, especially if you are coming from Canberra!
Glenlyon Dam is extremely popular with fisherfolk, as it is a well known Murray Cod fishery. Hence, the area has a very well set up tourist park, (http://glenlyondamtouristpark.com.au) with camping and accomodation options.