Last year we had made an effort to locate the ruin, but were defeated by a rough, unpaved road only suitable for a 4-wheel drive, certainly beyond the capacities of our little Echo.
On a recent sunny Sunday, we decided to try hiking in instead. Taking a wrong fork that we thought would lead there, we found ourselves eventually at a power-line pylon on the cliff edge and had to retrace our steps to the other fork. This one led us in the right direction and we emerged in the field we'd seen from the train.
The old mansion now has neither roof nor floor, but you can see that it was once a substantial property in the Gothic style, with walls of rough-cut sandstone and a square tower, now engulfed in ivy. Traces of garden beds, paths and shallow flights of steps are all overgrown with weeds and self-seeded saplings.
There is still a bit of old paving near the entrance,
and a motto carved on the lintel, by someone who wasn't very conversant with Latin. It should read Vi et Anima, meaning "By Strength and Spirit".
A cluster of agaves with strikingly tall flower spikes, the flowers long spent on this late autumn day, still stands among artfully jumbled rocks on the verge of bushland.

After a little on-line research, I found this old photo of the house as it once was.

Accompanying information says that it was built with stone quarried on the site. The estate included a tennis court, a large dam, and a circular driveway. Bushfires, and later vandalism, were responsible for its destruction, and the 164-hectare property has been derelict for several decades. Sir Henry Parkes was only one in a succession of owners; it is now owned by a development company which has plans for a gated community there, but on a positive note also intends to restore the house and grounds.