|Guardian Exchange was an underground telephone exchange built in Manchester in the 1950s. It was built together with the Anchor Exchange in Birmingham and the Kingsway exchange in London to provide hardened communications in the event of nuclear war. In common with most civil defence structures of the time it was designed to withstand atomic bombs although would not have survived a direct hit.|
The tunnels are now just used for BT cables. A fire in the tunnels on 29 March 2004 caused 130,000 telephone lines in Manchester to be cut off.