1984 – three égoutiers (canalisation workers) found a 85 cm long female crocodile in the égouts (canalisation) of Paris. Eleonora, by now a good two meters longer, is enjoying her live in the Aquarium de Vannes.
This is certainly the most interesting fact to learn during the visit of the Paris canalisation. After this first surprise of one of the biggest urban myths being true, the second is is the smellnessless and cleaniness of the place. The last is the surprisingly low number of rats (2/inhabitant of Paris city = 4 million) and that the directors of Ratatouille came to visit the canalisation to learn more about this city under the city.
Indeed, just as the streets above, every canal has the street sign and the houses have their numbers assigned mirrowing the city above and allowing a perfect on-the-spot intervention in case of problems.
In case you have an hour to spare during you next Paris visit (and if you speak French), it is definitely worth visiting les égouts.
La puce, die Welt and everything else 
i will go as i speake such good french
I’m sure they’ll appreciate the visit of such an outstanding English gentleman as you are!