A remnant of the cold war, now long abandoned a Royal Observer Corps observation post and its underground bunker on a hilltop near where I live at Trawsfynydd, North Wales. More info: http://www.subbrit.org.uk/cgi-bin/webdata_roc.pl?fid=987853951&query=%26cgifunction%3DSearch%26Pic1%3D*.jpg%26pagenum%3D63%26cgisort%3D3%26cgisortorder%3D0&cgifunction=form