Stop! Top Secret!

Warning! Security clearance is needed before you read on.
This looks like a ramp to a car park, but in fact it is the entrance to the new, covert headquarters for MI6...
Well, it is in the new Bond film, Skyfall, anyway.
I walk past here most days, and recognised it on the big screen as the location used for the spy's base.
The car park attendant denied being part of the British secret intelligence service, but I knew different...