A perfectly preserved 1919 station of the original Madrid metro, closed in 1966 because the curved platforms could not be lengthened for longer trains. The station was sealed and forgotten for four decades — and then, in 2008, restored exactly as it had been left and reopened as a small museum-platform called the Andén 0.
The tiled walls still advertise the cigarette and chocolate brands of the 1930s, the ticket booth still has its 1960s machines, and trains still pass through every two minutes — passengers in the modern carriages can briefly see the tiled platform and visitors on the platform can see the trains rattle past behind a glass wall. Free entry. Open Thursdays to Sundays only; check the website for hours.