This place would have commanded a fantastic view if there were no trees about. You can't see much of the surrounding area due to the trees and the house, but it's in what I believe they call 'a prominent position'. It would have been visible for quite a distance I'd think.
There are a few larger stones lurking about in the field, some down the bottom of a steep slope that forms the western edge of the field. Another is about 50m to the north, these may have been part of the structure, I don't know enough about these kind of monuments to pass judgement on the matter.
What I do know is that it has a nice feel, and the Oak doesn't detract from the place at all. In fact, I'd love to see the place in the winter, it would look fantastic in the snow at sunset.
The folks at the house were more than happy to allow access, providing visitors ask.