A bit of a puzzle inspired by a recent trip to Canberra.
Firstly you need to identify the object in the listing (somewhere in Wollongong), gather some information and project where GZ will be. Hopefully the clue isn't too hard to locate- if you're from out of town you might struggle a little more but I think you'll get there.
At the base of the object in the image provided there are three plaques. Look at the one on the right hand side. There are two years mentioned. Lets call those numbers ABCD-EFGH.
GZ can be located at a distance of (B-E)BF metres away, on a bearing of EF(A+C+D+G+H).(A+C+D+E+G) degrees from this location.
The maths will get you pretty close- see the hint to narrow things down a little when around GZ. Good luck!