One of eight deep-level bomb shelters built around London during World War II, that at Clapham North was constructed between November 1940 and 1942. At one point the large shelter housed 8,000 troops in a labyrinth of stairwells and tunnels that stretched for more than two miles about 30 meters underground, but it has since fallen out of use.

The shelter hasn't been utilized for the protection troops from bombs for many decades and it now sits empty underneath the Clapham North tube station, which is shown in the pictures. The station opened more than four decades before the shelter was built beneath it. An extension of the City & South London Railway to Clapham Common one stop to the south, the Clapham North station is one of only two remaining in the city that has an island platform in the station tunnel.

All eight of the deep-level air raid shelters feature a pair of parallel tunnels 16 feet and six inches in diameter and 1,200 feet long. Ten tunnels were planned - to house a total of 80,000 troops - but only eight were constructed. Today, the Clapham North tunnel is the only one that sits unused. The other seven have been converted into shelters for data storage. The Clapham North tunnel is too damp for the proper storage of media, so it sits empty.