Coombe Park near Whitchurch-on-Thames is a now abandoned country houe with 18th and 19th century origins, but mostly dating from 1986.
The Explore:
Unfortunately I was not able to access the main mansion because it has been sealed up well. I was however able to wander around the grounds without being disturbed by avoiding the little black motion sensors that are dotted around the place.
N.B: the house has been redeveloped, and likely demolished.