The Illawarra's largest icon can be seen for miles and miles. Currently this structure is a sleeping giant, but over the years it has been a place of much debate.
Getting to GZ shouldn't be too hard, but once you're there the coords will only put you in the general area, the rest is up to you. The cache is log only, it does have a pencil inside, but it might pay to bring a pen.
While you're there, work out how high this thing is?