Note: The museum is closed for extensive renovations until early 2020.
If you want to get a better idea of Jean Valjean’s underground ordeal in Les Misérables, take a trip through Paris’s sewer museum. Though you won’t actually get on a boat, you will be able to walk through a short stretch of the city’s 2,400 km (1,490 miles) of sewers (don’t worry, you’ll be on a raised sidewalk on the side of the, uh, water), which should give you a pretty good idea of the different types of passageways and equipment that exist in this underground domain. After the renovations, interactive circuits of displays will explain the history of the city’s water supply and waste disposal issues (this was no joke; for centuries, the lack of a proper sewage system helped spread diseases like the Black Plague), as well as technical aspects of this stinky world. Because it’s underground and part of the working system, the museum closes when the Seine is high.