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 - all believed to provide hardened communications in the event of nuclear war.
The Guardian Bunker has been called the "Best kept secret in Manchester" and its existence was only outed in 1968, 14 years after initial construction.
The tunnels are known to be used for British Telecom cables. The exchange rose to prominence in March 2004 when a fire in one of the tunnels caused 130,000 telephone lines in Manchester to be cut off. Ambulance and fire service calls around the North West region were also specifically affected.
