Ghosts Of Past Spies Haunt London Underground Tunnels

Deep beneath the London streets lies a network of disused tunnels, once home to British spies and a secret long-distance telephone exchange (Credit: AFP)

Behind a blue door in a narrow London passage lies a little-known network of tunnels deep underground, once home to British spies and a secret long-distance telephone exchange.

Thirty metres (100 feet) below the UK capital's bustling streets, all that can be heard in the tunnels built to withstand a nuclear attack is the rumble of the London Underground's Circle Line.