Musée des Egouts de Paris

If you want to get a better idea of Jean Valjean’s underground ordeal in “Les Miserables,” 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. There’s also a film and a circuit of displays that 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 is indeed stinky—delicate noses should think twice before entering.