Imperial War Museum London in Southwark

You're standing outside the Imperial War Museum in London. Start with the building itself: a grand portico, topped by a dome that looks unusually tall. There's a reason for that. This was once the Bethlem Royal Hospital, a psychiatric hospital also known as Bedlam. The building was completed in 1814, and between 1844 and 1846 the dome was added, above the hospital chapel. Before the museum moved in, in 1936, the two extensive side wings were demolished. That's why the dome now looks too big for the building. The land that was freed up became the park around you, Geraldine Mary Harmsworth Park, named after the mother of Lord Rothermere, who had bought the site.