Ok - its the DoomRamp, and it ain't that secret. Nice wee session - loads of dropping in and a couple of 50-50 dropin attempts, dutifully pussied out on by me, of course. Ho hum.
(and if you don't know what TURNSTILE is then either ask The Gaffer or look here http://www.burlingtonbunker.co.uk/ . Corsham ain't all that it seems).