Several years ago I took the tour of the Paris sewers and I enjoyed the experience. It was interesting, and not the least bit creepy. A very interesting book to read is The city as a work of art : London, Paris, Vienna by Donald Olsen. In this book Olsen explains the changes that occurred in the 19 century ( the sewer being one of many ) as a theater of historicist consciousness.

Best Regards, Sheryl, NYC