I think you need to be 100 klms from any city to have even a chance of truly dark skies.
There are a couple of places that fit the bill within two hours of Newcastle (but of course I can't tell you where they are)

Last night we were observing 50 kms north of Canberra and whilst it was an excellent evening, we could actually see the light domes of Canberra, Yass and Goulburn. Canberra being by far the worst.
I was a little eerie to be out there on a private property given that the farmer dropped in to let us know they would be out shooting rabbits.