To those from the Western hemisphere, it’s always fascinating to hear that some homes and businesses from the times of the Greek philosophers still have inhabitants, and then you remember that the Western hemisphere is itself not without its own examples, for example some Mexican villages still have temples from the times of the Mayans.
The oldest extant building is circa 1832, so ~192 years old - not much compared to some places but doing well for an Australian building.
Perth?
True story - I moved from Scotland to Perth when I was 6. A few months later I visited Tranby House, one of the oldest buildings in Perth at around 1830. I remember thinking to myself that our house in Scotland before we moved was older than that (circa 1800)
Canberra actually - it’s an old dairy building that’s part of Duntroon (one of the original homesteads of the region but more well known for being where RMC/ADFA is). It pre dates Canberra by a good bit though since development of the city only really began to gain traction in the 1920s.