Situated in the west of Bosnia on the border with Croatia, Objekat 505, as it was officially known, was the largest underground airport in the Balkans. The primary purpose of the Objekat 505 was to house a long-range radar early warning system, akin to NORAD, as well as to provide a strategic command center for the country’s defense.
The Kelvedon Hatch Secret Nuclear Bunker at Kelvedon Hatch, in the Borough of Brentwood in the English county of Essex, is a large underground bunker maintained during the cold war as a potential regional government headquarters.
Danish artist Thomas Dambo has been building stuff using trash and recycled materials since an early age, starting with smaller sculptures such as birdhouses and furniture to bigger pieces such as the six “Forgotten Giants” he recently installed around Copenhagen.
Royal Air Force Menwith Hill or more simply RAF Menwith Hill is a Royal Air Force station in England which provides communications and intelligence support services to the United Kingdom and the United States of America. The site contains an extensive satellite ground station and is a communications intercept and missile warning site and has been described as the largest electronic monitoring station in the world.
The Mount Weather Emergency Operations Center is a civilian command facility in the U.S. state of Virginia, used as the center of operations for the Federal Emergency Management Agency (FEMA). Also known as the High Point Special Facility (HPSF), its preferred designation since 1991 is "SF".
Metro-2 in Moscow, Russia, is the informal name for a purported secret underground metro system which parallels the public Moscow Metro. The system was supposedly built, or at least started, during the time of Joseph Stalin and was codenamed D-6 by the KGB.
Balaklava at one time worked at the base; even family members could not visit the town of Balaklava without a good reason and proper identification. The base remained operational after the collapse of the Soviet Union in 1991 until 1993 when the decommissioning process started.