The bunker seemed to be spewing mist,as a furnace spews smoke.
NB:But,a short while later,this image caused a lady driver to suddenly go white,then drive off at high speed!
The house on top of the hill,is the aptly named Hill Hall,former Mansion,former prison and former dilapidated shell.Now,very expensive flats.That's where the lady driver had property.
see http://www.english-heritage.org.uk/server/show/nav.12114
see http://www.zipworld.com.au/~lnbdds/home/smyththomassirbiog.htm
see http://www.hobbscrossgolfcentre.com/location_map_dire.htm