The Secret War exhibition reveals the clandestine world of espionage, covert operations, and the work of Britain's special forces.

It shows how Britain's secret government agencies, MI5 and MI6, have developed since their establishment before the First World War, and how specialist communications technology has been used to gather intelligence and break top-secret codes.

The work of the Special Operations Executive is covered through exhibits and film footage which provide an insight into the training of SOE agents to enable them to operate in enemy-held territory in the Second World War.

Among the exhibits are bottles of invisible ink used by German spies in the First World War, an original German Enigma cipher machine, codebooks, SOE sabotage devices, and a secret radio used by MI6 agents during the Cold War. Files on individual agents and operations can be accessed through interactive videos.

The exhibition also looks at the history of highly trained elite special forces such as the Special Air Service and the Long Range Desert Group. It includes firearms and equipment used in the Second World War and in more recent conflicts such as the Falklands and the Gulf. There are two dramatic audio visual presentations; The Benina Raid, a daring SAS and LRDG attack on a German airfield in North Africa in 1942; and a reconstruction of Operation 'Nimrod', the SAS operation to release hostages held in the Iranian Embassy in London in 1980.