Admiralty Citadel, London, England

The Admiralty Citadel was once described by Sir Winston Churchill as a "vast monstrosity" but what exactly was the purpose of this imposing London fortress.

Admiralty Citadel




United Kingdom

Near Trafalgar Square, Whitehall and the Mall stands a large World War Two era Citadel. Above ground, the Admiralty Citadel is a rectangular, windowless fortress covered in creeping ivy. For a location in the centre of London facing St James’ Park, it is still well camouflaged and relatively unknown.

Building the Admiralty Citadel

Constructed in 1940 and 1941, the Admiralty Citadel was a bomb-proof structure. Fitted with gun emplacements, the foundations sank 30 feet (9 metres) deep and the roof was 20 feet (6 metres) thick. Had the enemy invaded, it would have made an ideal stronghold in the city with underground tunnel links to Whitehall.

In London, it’s today known for its brutalism of design. During the war, Winston Churchill was one of its main critics.

A vast monstrosity which weighs upon the Horse Guards Parade.

Winston Churchill – Prime Minister of Great Britain.

Horse Guards Parade, London

The London skyline behind Horse Guards Parade taken from the site of the Admiralty Citadel built as a proposed fortress in 1940. Photo taken on 12th January 2014.

The Citadel today

Since then, the ugly appearance of the building in such a prominent position has even been a cause of debate in the House of Commons. Covered in creepers and vines in an attempt to camouflage the building, it’s sometimes barely noticeable. From the air, it blends into the nearby parkland as a grass lawn covers the roof. Even today, someone mows the roof lawn in summer months.

Admiralty Citadel, London

The Admiralty Citadel at Horse Guards Parade, London was built in 1940 and described by Churchill as a “vast monstrosity”. Photo taken on 12th January 2014.

Even today, the public do not know a lot about the history or even modern day usage of the citadel.

The Admiralty Citadel still falls under the jurisdiction of the Ministry of Defence. In 1992 the Citadel became the stone frigate HMS St Vincent. Since then, the Royal Navy operated from the citadel as an Admiralty Communications Centre.

Since 1998, a series of mergers saw the building come under the control of government sub-contractors. It is now known as Marcomm Comcen (St Vincent). There is no public access to the building.

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