Fronted by a pair of intimidating 15in naval guns, this riveting museum is housed in what was the Bethlehem Royal Hospital, a psychiatric hospital also known as Bedlam. Although the museum’s focus is on military action involving British or Commonwealth troops largely during the 20th century, it rolls out the carpet to war in the wider sense. Highlights include the state-of-the-art First World War Galleries and Witnesses to War in the forecourt and atrium above.

Indeed, Witnesses to War is where you'll find everything from a Battle of Britain Spitfire and a towering German V-2 rocket to a Reuters Land Rover damaged by rocket attack in Gaza and a section of the World Trade Center in New York.

On the 1st floor A Family in Wartime poignantly follows WWII through the experiences of the real-life Allpress family of Stockwell. In Secret War on the 2nd floor, there’s an intriguing rifle through the work of the Secret Operations Executive (SOE), such as rubber soles resembling feet worn underneath boots to leave ‘footprints’ on enemy beaches. One of the most challenging sections is the extensive and harrowing Holocaust Exhibition (not recommended for under 14s), the entrance of which is on the 4th floor. Curiosities of War is a jumble sale of fascinating items, such as a makeshift bar used by the Dam Busters crew in 1943, taken from the museum's collection. Other galleries and exhibition spaces are given over to temporary exhibitions (check the website for details).

Augustus Pugin, famous Gothic Revival architect of the interior of the Houses of Parliament, was once a patient in the psychiatric wards of the former Bethlehem Royal Hospital. The hospital moved in 1930 and the building became home to the Imperial War Museum in 1936.