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 ...

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.

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 ...

Deep beneath the London streets lies a network of disused tunnels, once home to British ... they needed a deep level telecommunications exchange," said Murray. The site, spread over 8,000 square ...

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.