Kelvedon Hatch Secret Nuclear Bunker
Inside Kelvedon Hatch Secret Nuclear Bunker
Hidden (but recently signposted) underneath a fake farm house in Brentwood, England.
 
The bunker has served three functions during its lifespan, but the most recent and most interesting was as a standby government HQ in the event of a nuclear war.
 
The bunker was decommissioned in the 1980's but is available for general admittance.
 
Information on the not so secret bunker can be found here:
www.secretnuclearbunker.com