Behind a blue door in a narrow London passage lies a little-known network of tunnels deep underground ... some of the ...

A sprawling network of secret underground tunnels is being transformed into a major new London tourist attraction. Hidden 40m ...

Deep beneath the London streets lies a network of disused tunnels, once home to British ... they needed a deep level telecommunications exchange,” said Murray. – Forgotten offices – The ...

Behind a blue door in a narrow London passage lies a little-known network of tunnels deep underground ... they needed a deep level telecommunications exchange," said Murray.

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.

Deep beneath the London streets lies a network of disused tunnels, once home to British spies and a secret ... of the telecommunications exchanges got bombed, they needed a deep level ...