A once-secret 1940s tunnel complex under the centre of London that housed military intelligence and linked the Cold War hotline phone between Washington and Moscow has been put up for sale.
The complex was dug in 1942 as a bomb shelter for 8,000 people during World War II but was taken over by military authorities as a communications and intelligence centre.
The Post Office later took over the property as a more secure location for its long distance phone exchange, including the 1950s hot line directly connecting the White House and the Kremlin.
Former state telephone monopoly BT says the 1.6 kilometre long network of tunnels below Chancery Lane underground station is now surplus to requirements.
In the 1980s the Government used part of the complex as a temporary backup for its top secret Pindar war control bunker.
It has a total floor area of around 7,100 square metres but can only be reached by two street-level lifts, restricting its potential use.