During the World Exposition in 1867 the sewers of Paris were open to the public for the first time. At that time, visitors were given locomotive drawn wagon tours and until the '70s, tour boats.

The sewers are identical with the streets above them, they even have street signs with the corespondent street. They are large enough for people to navigate around the entire sewer system and it seem that people are very fascinated with this out of the ordinary museum.

It's complex and surprising in many ways, so take the time to pay a visit!