Well, this is disappointing. You'd think a cautious author who lived in Paris would have at least a vague ideas of how arrondissements work, but no.

Place Cachée is, and I quote this very wiki, "located at the juncture of Rue Richer and Rue Girardon." It also mentions how Boulevard Voltaire is also part of this nonsensical place.

However, if you open a map, you would quickly find that not only do rue Richer and Girardon NOT cross paths, but they aren't even remotely close, and Boulevard Voltaire is many times as unlikely to be connected to them.

I understand that in a story, your disbelief is suspended for the sake of making a good story… but come on. If they clearly don't work, just pick other streets. Because all Parisian viewers would tell you how incredibly undocumented the writers were, a real paradox for a high-budget movie which should provide all that the team needs.

And you can't even explain that Place Cachée is in the Parisian underbelly, an underground city, which would be just about the coolest thing this movie would have, because clear shots of the sky are visible !

Just… an incredible waste of potential in my opinion.