Your wondering- am I out of my mind right? Absolutely not! I loved this attraction. Called the Musée des égouts de Paris (otherwise translated as the Museum of the Sewer) takes you to a live working sewer. No, it does not smell, and they give you hard hats to keep from getting wet. Tell your friends you visited a sewer! You walk on a catwalk above the cities untreated sewer water, and there are pictures that walk you through the development of the sewer. They tell you all about the process of how the sewer works, and also how in the past waist was dealt with. Les Misérables was inspired here as well. The nearest metro stop is Alma-Marceau (line 9) on the Right Bank; after leavin the station, cross the river to the Left Bank and turn left at the Quai d’Orsay. It is free with the museum pass, or only 6bucks us to visit.

Check out http://europeforvisitors.com/paris/articles/paris-sewers-museum.htm for more information.

Yes that is raw sewage- I promise it doesnt smell.