The area between Ringwood and Park Orchards contains a multitude of small hills, valleys and watercourses with the Mullum Mullum Creek running right through them from Ringwood to the Yarra at Tikalara Park near Eltham. This area was once considered unsuitable for general housing and the Mullum Mullum Creek valley had been reserved for future freeway construction (because, in the '50s it was a lot easier to build a road along such an existing feature). Fortunately, after considerable protest, the freeway is now going through a tunnel under the valley and this impressive wildlife corridor will be preserved in its natural state.
A fortunate side-effect of this previous zoning as a freeway is that no so-called "improvements" (boardwalks, paths, plantings, etc) have been made to the valley and it is in a very much undeveloped state today.
When we first moved into this area, I was intrigued by some of the terrain, and particularly by a valley which runs to the NE from GZ which, at the time, and from further up the valley, looked like a scene from the Austrian Alps - so it seemed a good place for us to locate a cache once we discovered geocaching. The cache is located near the junction of a small stream flowing out of this valley and the Mullum Mullum Creek.
Access is either from the Heads Rd bridge to the south, or from the Park Rd bridge to the north - it is pretty much equidistant from them both, but the terrain from the south is a bit tougher, while it is difficult to pick up the path from the north. The area abounds in birdlife, and a variety of other native animals are frequent visitors to the area. While travelling this path, and especially around GZ, be particularly vigilant for snakes - it's real tiger snake country and I've also seen white-lipped snakes (not dangerous) in the area.
The cache is a 1L Sistema container with the usual swaps.
Good luck!