Military citadels under London

A number of military citadels are known to have been constructed underground in central London, dating mostly from the Second World War and the Cold War. Unlike traditional above-ground citadels, these sites are primarily secure centres for defence coordination.

A large network of tunnels exists below London for a variety of communications, civil defence and military purposes; however, it is unclear how these tunnels, and the various facilities linked to them, fit together, if at all. Even the number and nature of these facilities is unclear; only a few have been officially admitted to.

Pindar
The most important military citadel in central London is Pindar, or the Defence Crisis Management Centre. The bunker is located underneath the Ministry of Defence (MOD) Main Building in Whitehall, five floors below the buildings previously existing South Citadel. Construction took ten years and cost £126.3 million. Pindar became operational in 1992, two years before construction was complete. Computer equipment was much more expensive to install than originally estimated as there was very little physical access to the site. Pindar can house a maximum of 400 personnel and provides protection against conventional bombing, sabotage, biological and chemical attack, flooding, EMP attack, and the effects of blast, radiation, and EMP from "all but a direct hit or very near miss" by nuclear weapons.

Pindar has two floors; the lower floor contains the Ministry of Defence's Joint Operations Centre, and the upper floor consists of:


 * Government Emergency Rooms (comprising the Prime Minister, Secretaries of State, the Cabinet Secretary, and some Permanent Secretaries)
 * An element of the Joint Intelligence Organisation
 * A telecommunications secretariat and a Cabinet Office Communications Centre (COMCEN) element

Pindar is connected to Downing Street and the Cabinet Office by a tunnel under Whitehall; the tunnel predated the bunker and was already used as a conduit between the Cabinet Office and the MOD Main Building, with Downing Street access being added during Pindar's construction. The tunnel can be used by government ministers to enter Pindar without risking the press attention, and subsequent damage to national morale, that would ensue if the bunker was openly entered and, as was the case when the bunker was used for meetings on the 1999 NATO bombing campaign in Yugoslavia, without the risk of encountering hostile demonstrations. When answering written questions about Pindar, which included a question on the extent of lift and staircase access to the bunker and on whether there was any connection to transport systems, then-Armed Forces Minister Jeremy Hanley would say only that there were "sufficient means of access and egress" and denied that the bunker was connected to any transport system; he also said that there were means of leaving Pindar should the MOD Main Building collapse on top of it, but did not state the details of these.

Although Pindar is not open to the public, it has had some public exposure. Between September 2006 and April 2007, the British photographer David Moore carried out an extensive photographic survey of an underground facility that was widely believed (and strongly hinted) to be Pindar, with Moore stating in later years that Pindar was indeed the facility depicted in the photographs. The photographs, which were published as The Last Things in 2008 as well as being exhibited in 2008 and in 2009, show that the facility has stores ranging from CBRN equipment to personal hygiene items. It has bunks for up to 100 military officers, politicians and civilians as well as communication facilities, a medical centre and maps.

The bunker is named after the ancient Greek poet Pindar whose house was the only one left standing in Thebes following the city's destruction in 335 BC.

Admiralty Citadel
The Admiralty Citadel, London's most visible military citadel, is located just behind the Admiralty building on Horse Guards Parade. It was constructed in 1939 by the Ministry of Works with the architect W. A. Forsyth as a consultant. It was designed as a bomb-proof operations centre for the Admiralty, with foundations 30 ft deep and a 20 ft thick concrete roof. It is also linked by tunnels to government buildings in Whitehall.

Its brutal functionality speaks of a very practical purpose; in the event of a German invasion, it was intended that the building would become a fortress, with loopholed firing positions provided to fend off attackers. Sir Winston Churchill described it in his memoirs as a "vast monstrosity which weighs upon the Horse Guards Parade". In 1955, a question was asked in the House of Commons about mitigating its harsh appearance. The Minister of Works, Nigel Birch, describing it as "a hideous building", announced that the heavy gun positions were to be removed and that planting Virginia creeper (some sources identify the plants as Boston ivy ) would help to mask the concrete walls. In the same debate, a suggestion by MP John Tilney that a variety of plants be used was rejected by the minister on the grounds that it would "make it like an old-world tea garden". It became a Grade II listed building in December 1987.

In 1992 the Admiralty communications centre was established here as the stone frigate HMS St Vincent, which became MARCOMM COMCEN (St Vincent) in 1998. The Admiralty Citadel is still used today by the Ministry of Defence.

Cabinet War Rooms
The only central London citadel currently open to the public is the Cabinet War Rooms, located in Horse Guards Road in the basement of what is now HM Treasury. This was not a purpose-built citadel but was instead a reinforced adaptation of an existing basement built many years before.

The War Rooms were constructed in 1938 and were regularly used by Winston Churchill during World War II. However, the Cabinet War Rooms were vulnerable to a direct hit and were abandoned not long after the war. The Cabinet War Rooms were a secret to all civilians until their opening to the public in 1984. They are now a popular tourist attraction maintained by the Imperial War Museum.

The section of the War Rooms open to the public is in fact only a portion of a much larger facility. They originally covered three acres (1.2 hectares) and housed a staff of up to 528 people, with facilities including a canteen, hospital, shooting range and dormitories. The centrepiece of the War Rooms is the Cabinet Room itself, where Churchill's War Cabinet met.

The Map Room is adjacent, from where the course of the war was directed. It is still in much the same condition as when it was abandoned, with the original maps still on the walls and telephones and other original artefacts on the desks. Churchill slept in a small bedroom nearby. There is a small telephone room (disguised as a toilet) down the corridor that provided a direct line to the White House in Washington DC, via a special scrambler in an annexe basement of Selfridges department store in Oxford Street.

Q-Whitehall and tunnel network
Q-Whitehall is the name given to a communications facility under Whitehall.

The facility was built in a 12 ft (3.7 m) diameter tunnel during World War II, and extends under Whitehall. A similar facility was constructed in a tunnel that ran parallel to the Aldwych branch of the Piccadilly Line and was known as Trunks Kingsway (Kingsway Telephone Exchange). The project was known as 'Post Office scheme 2845'. A detailed description, with photographs, was published just after the war in the January 1946 edition of The Post Office Electrical Engineers' Journal.

Sites equipped with unusual amounts of GPO/BT telecommunications plant are given a BT site engineering code. This site's code was L/QWHI.

The site provided protected accommodation for the lines and terminal equipment serving the most important government departments, civil and military, to ensure the command and control of the war could continue despite heavy bombing of London.

At the northern end, a tunnel connects to a shaft up to the former Trafalgar Square tube station (now merged with Charing Cross station), and to the BT deep level cable tunnels which were built under much of London during the Cold War. At the southern end, an 8 ft (2.4 m) diameter extension (Scheme 2845A) connects to a shaft under Court 6 of the Treasury Building: this provided the protected route from the Cabinet War Room. This was known as Y-Whitehall. The 8 ft tunnel was further extended (Scheme 2845B) to the Marsham Street Rotundas. This extension housed the 'Federal' telephone exchange which had a dialling code of 333 from the public network. In the 1980s it housed Horseferry Tandem which provided a unified communications system for all government departments as well as the Palace of Westminster.

Access to the tunnel is gained via an 8 ft (2.4 m) lateral tunnel and a lift shaft in the nearby Whitehall telephone exchange in Craig's Court. A further entrance is via the deep level portion of the Admiralty.

Spur tunnels, 5 ft (1.5 m) in diameter, were built to provide protected cable routes to the major service buildings either side of Whitehall.

The Whitehall tunnels appear to have been extended in the early 1950s. Some official documents refer to a Scheme 3245: this is the only numbered tunnel scheme that has never been officially revealed or located by researchers. Files in the National Archives which may relate to this have been closed for 75 years and will not be opened until the 2020s.

The journalist Duncan Campbell managed to get into the tunnel network and described his exploration in the 19-26 December 1980 issue of the New Statesman. He found more than thirty access shafts for the network as well as entrances to Q-Whitehall (below Trafalgar Square), various government department buildings including Downing Street, the Cabinet Office, the Ministry of Defence, the Old War Office, the Admiralty, the Treasury, and the Department of the Environment, the old Cabinet War Rooms, and various telephone exchanges, and created a map of both this network and the deep level cable network based on his investigation. Those shafts that could be readily accessed by the public were promptly sealed up following the publication of Campbell's article.