The Arch in Devil's Coach House, a vast open-ended chamber in the Jenolan caves.
The weather was mostly clear and despite the cold temperatures minimum 1 deg cel, I didn't have any issues with dew on the lenses. I had some disposable warm packs just in case to sticky tape around the lens in the event that it did dew up. I've read this works although I haven't tested it yet.
This was pretty much the shot I'd been wanting to take all night, the Milky Way was positioned just where I wanted it, pure dumb luck on my behalf.
Thanks for looking