A disused Tube station where Winston Churchill secretly took refuge during the Blitz is one of a number of hidden London Underground sites set to be opened to the public.
Down Street in Mayfair had a short life as a station from 1907 to 1932 but acted as a bomb-proof bunker for the prime minister during the Second World War.
He requested that living quarters were built there for his personal use and he hosted meetings with other politicians in the secrecy and safety of the station.
The location was also used by the Railway Executive Committee to co-ordinate the country's railways.
Dozens of staff lived and worked at Down Street, unaffected by any attacks occurring above ground.
Executives would enter and leave the station by travelling in the driver's cab of Piccadilly line trains which would stop next to a discreet entrance in the middle of a tunnel.
The station is one of several sites where London Transport Museum (LTM) will run guided tours.
Chris Nix, assistant director of collections and engagement at LTM, told the Press Association: "As well as an unexpected history and images that help them understand what this space would have looked like, it's the sense of place that visitors will get more than anything.
"You can't get a sense of what it would have been like to live and work here without having been here.
"This is the same of any of the Hidden London tours. The magic is going to the place and seeing it first hand."
A labyrinth of dark and deserted passageways under Euston station is also being unveiled as part of the latest Hidden London project.
Visitors will be able to view a gallery of preserved vintage advertising posters that have been concealed for over half a century.
Clapham South's deep-level Second World War shelter will also be opened.
Members of the public will be able to take the 180 steps below ground to a site used during the Blitz, by Caribbean migrants arriving in 1948 and even visitors to the Festival of Britain in 1951.
Hidden London will also feature London Underground's former headquarters at 55 Broadway near St James's Park.
The Art Deco building, which opened in 1929, is described as the capital's first skyscraper.
Tickets for all the tours will initially go on sale to LTM email newsletter subscribers on Tuesday.