The Rotundas in Marsham Street, London

It’s a testament to the dire straits Britain was in during the run-up to World War Two that two eyesores in London suddenly became prime real estate. In 1937, a gas company operating out of SW1 demolished two enormous gas holders, leaving two impossibly deep holes in the ground. At any other point in British history, the subsequent story would be about a battle between the local council and private contractors about who should fill in these pointless pits. But Interwar Britain was a place expecting mass-destruction to rain down from the sky at any moment. In such circumstances, two deep holes suddenly seemed less like a problem, and more like an opportunity. By 1940, the UK government had designated the pits as the site of a new, war-proof home for Britain’s civil service. By topping the holes with enormous concrete shells that could withstand a direct hit from a 500lb bomb, they created a subterranean underworld from where the business of government could function throughout the Blitz. Over 3,000 workers could shelter safely for up to three months, even as the rest of London succumbed to flames and bombs around them. Known as the North and South Rotundas, these massive bomb shelters became home to several vital departments. The Air Ministry, Ministry of Home Security, GHQ, and Intelligence Department all worked from the rotundas at one point or another. Domestic accommodation was installed for the Prime Minister, Winston Churchill, and his senior staff on the lowest floor of the North Rotunda. This area, known as Anson, incorporated a reserve Cabinet War Room, replacing another facility at Dollis Hill, known as Paddock, which was deemed unsuitable. This was where the cabinet would conduct the business of government should the rest of London be lost beneath a sea of fire. Naturally, it never came to this. The Blitz and Vengeance rocket campaign devastated parts of the UK capital, but never succeeded in reducing it to ash in the way that, say Coventry and Dresden were (these two cities were twinned in 1956 in a gesture of peace and reconciliation). Abandoned at the end of the war, the rotundas sat empty. A strange, hidden world, turning to dust deep beneath the sleepless streets of Britain’s largest city. In 1971, the Marsham Towers were completed on the site of the Rotundas, at the corner of Marsham Street and Great Peter Street. The abandoned wartime structures were incorporated into the base of the much maligned government building, and found a variety of uses including a civil service sports facility and a communication centre. Described by Nikolaus Pevsner as “the very image of faceless bureaucracy”, the towers were demolished in 2002 and have now been replaced by the Home Office facility, 2 Marsham Street. (For more information visit Subterranea Britannica.)