What should be done with the 40 disused ghost stations on the underground?
By Harriet Prest
BBC London TV
London has about 40 abandoned or relocated underground stations but should they be brought back to life?
London's Underground system plays a large part in our lives. Millions travel on it each day, its map is an icon around the globe and it is the world's oldest underground system.
Some Londoners go one step further and harbour a fascination for disused tube stations.
BBC London took a trip along the Piccadilly Line of the past to try to find out what so-called 'ghost stations' are used for now, and, what Londoners think should happen to them in the future.
Tours around ghost stations are now almost impossible to arrange as many of the abandoned sites are unsuitable for visitors because of health and safety concerns.
London Underground also told us access below ground is now more carefully monitored since the 7/7 bombings.
But we were able to gain access to Aldwych Station which closed in 1994.
It's now regularly used as a filming location for programmes like Spooks, and feature films including Harry Potter and Atonement.
The idea is, there's an adventure just below our feet, there are stations all over the place, it's fantastic down there.
Howard Collins of London Underground said: "People have always had a huge fascination for these places. They are not empty, if you go behind the scenes, you will see they store rails and materials, are used for training and testing, or they are used for ventilation shafts."
Some Londoners would like to see old stations put back into use.
Adrian Davies lives just round the corner from the old 'Brompton Road' - a station you probably never even knew existed.
The only giveaway is the classic red-brick façade that suggests a history connected to the tube.
This station closed in 1934 due to a lack of passengers and its proximity to Knightsbridge and South Kensington.
Adrian explains: "It's screened off by sooty yellow brick walls from passing trains so you can't see it very well as you go through from Knightsbridge to South Kensington."
Adrian now wants to see the station re-opened: "While this station saw little passenger traffic in the 1930s times have changed. There are a lot of tourists, a lot of shoppers, I think it would be a busy station today and take some of the pressure off other stations on the line."
Another man with a plan is Ajit Chambers.
We met him outside Down Street which stopped taking passengers in 1932.
Inside Aldwych station which closed in 1994
Above ground the façade is intact and the building is now home to a Mayfair newsagent.
Winston Churchill bunkered down in the station's corridors occasionally during the war when the Cabinet War Rooms couldn't be used.
Ajit wants to tap into this kind of history, and is seeking permission to open disused underground stations up as museums.
He wants to offer people the chance to go and explore the 'ghost' stations: "The idea is, there's an adventure just below our feet, there are stations all over the place, it's fantastic down there. It's one of London's assets and we need to use it."
We asked Howard Collins from London Underground what he thought of Ajit's proposal: "It's a great idea, but if you've been to some of these sites, many haven't been opened for 70 years.
"To make them safe, even for visits, requires a lot of resources and special arrangements.
"Our focus is upgrading the system. We are spending billions of pounds of investment: upgrading with new trains; adding air-con trains on some lines and working on track signalling."
It seems, for the time being, the only chance you may have to see a ghost station on the underground is by keeping your eyes peeled out of the carriage window and waiting for a flash of light that suggests there may be a hidden world behind the tunnel walls.
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