display on sewer inhabitants...
The museum is located in the sewers and is actually pretty interesting. At the beginning there is a somewhat boring display on water in Paris - how it circulates, how it gets to our apartments, how it is cleaned, etc - but then there is a large and interesting display on the history of the sewage system in Paris, starting in the Gallo-Roman period and continuing to present day.
a main sewer tunnel
Since the museum is located in a section of the actual sewer system you also get to see the different kinds of sewage tunnels and you get to have an idea of how the system actually works. The only problem is the somewhat unpleasant smell, but it's not too bad.
smaller sewer tunnel
All in all, an interesting and different museum which is definitely worth a visit!