Paddock is the codeword for an alternative Cabinet War Room bunker for Winston Churchill's World War II government located in Brook Road, Dollis Hill, northwest London under a corner of the Post Office Research Station site. It was constructed in total secrecy in 1939 but only rarely used during the war, with only two meetings of the War Cabinet being held there. It was abandoned in 1944.
It comprises some forty rooms on two floors, is semi-derelict with original equipment abandoned and rusted, and a certain amount of water ingress which is kept at bay by an electric extraction pump.
Paddock has had various, intermittent uses since (including a brief period where what is thought to be the map room was used as a Post Office staff social club) but otherwise the site remains largely disused and empty as it was when it was decommissioned at the end of World War II.
The bunker is owned by Network Housing, an affordable housing association which is responsible for the properties now occupying part of the former research station site above, and is open to the public two or three times a year, with free guided tours provided by volunteers from the Subterranea Britannica organisation. It featured on the Channel 5 programme, Underground Britain.
Coordinates: 51°33′44″N 0°14′19″W / 51.562194°N 0.238586°W