A once-secret 1940s tunnel complex under the centre of London that housed military intelligence and linked the cold war hot line phone between Washington and Moscow has been put up for sale.
Former state telephone monopoly BT says the one mile long network of tunnels below Chancery Lane underground station is now surplus to requirements.
The complex was dug in 1942 as a bomb shelter for 8,000 people during the Second World War, but was taken over by military authorities as a communications and intelligence centre.
The Public Records Office used the site, known as Kingsway Tunnels, after the war to store historic documents. The Post Office later took over the property as a more secure location for its long distance phone exchange, including the 1950s hotline directly connecting the White House and the Kremlin.
When telephony was split from the Post Office, the tunnels passed to British Telecom, now privatized and known as BT.
In the 1980s the government used part of the complex as a temporary backup for its top secret Pindar war control bunker.
Sales agent Farebrother said there had already been a lot of interest in the now disused property.
Access to the mile-long system of horizontal and vertical shafts is through unmarked doors in the street on High Holborn.
The site is fully equipped with electricity, water supply and ventilation equipment.
BT put the site up for sale in 1996 but failed to find a buyer, but now the company hopes to find a government department or large company to move in and make the site productive again.
Elaine Hewitt, group property director for BT, said: "We are looking for a purchaser with the imagination and stature to return the tunnels to productive use.
"The site has the most fantastic history and, now that we have no requirement for it for telecommunications use, it is right that we should offer it to the market."
The unique nature of the site means it is unsuitable for conversion into a hotel or office, BT said.
BT hopes the sale could attract offers of about £5m.
