Disused London Underground stations are set to be sold off to become a network of tourist attractions, shops, museums and hotels, according to reports.
Companies will vie for the opportunity to buy the disused horse tunnels and tube stations from Transport for London (TfL), which owns 750 tunnels.
Some of the tunnels housed migrant workers in the 40s and others doubled up as air raid shelters during the Second World War.
The idea was first floated back in 2009 by former Barclays executive Ajit Chambers, 41, who believes the network is worth £3.6bn, reports the Evening Standard.
He discovered an old map of "ghost" stations five years ago and founded the Old London Underground Company to pursue his vision to renovate the stations, delivering revenue directly to TfL without disrupting the current rail service.
Mr Chambers has identified 34 possible sites, but the first phase of his plan involves 13 flagship stations, which will be converted into art galleries, nightclubs and possibly even a National Fire Brigade museum.
According to the Daily Telegraph, Mr Chambers has four investors on board, including Duncan Vaughn-Arbuckle, the founder of Vinopolis, London's wine museum.
However, TfL says there is "no affiliation" with him and that it will not show "any prejudice ahead of a public tender".
The paper adds that TfL has already begun some conversions, with the tunnels below Clapham North being home to a herb farm, and Waitrose aiming to run a service where customers pick up goods from fridges at sites like Chalfont & Latimer on the Metropolitan line.