Beneath the cobblestones of the Castle District lies one of Budapest's most extraordinary hidden spaces: a warren of tunnels and chambers that served as a functioning hospital through the worst weeks of the Second World War, then sat frozen in time as a Cold War nuclear shelter for half a century. The guided tour takes you through wards lined with period medical equipment, past operating theatres and storage rooms, to the bunker section with its decontamination chambers and sealed blast doors.
The wax figures throughout the hospital section are more lifelike than most such recreations and the setting — cool, dim, faintly damp — does real work. By the time you reach the nuclear bunker, the sense of being inside a secret that the city kept from itself for decades is genuinely strange. Tours leave regularly and last about an hour; the entrance is on Lovas út, a short walk from the funicular.