A flight of steps down from St James's Park leads to a low-ceilinged warren of rooms where Churchill, his War Cabinet, and the joint planning staff ran Britain through the Second World War. The site was a working bunker from August 1939 to August 1945, then sealed up and left untouched until it opened as a museum in 1984. The Map Room, the Cabinet Room, the transatlantic telephone room (a cleverly disguised lavatory door), and Churchill's own bedroom all survive as they were used.
The integrated Churchill Museum, opened in 2005, is one of the finest single-person museum experiences in London — including a 15-metre interactive table tracing his life year by year, his original cigars, his lecture notes, and the famous brown velvet "siren suit". Allow at least two and a half hours.
This is one of the most consistently crowded museums in London. Book the first slot of the day and arrive ten minutes early; by 11am the queue can stretch around the building. Audio guides are included.