Pay close attention to the glass building to your right, just before the organic grocery. Please stop here and look down into the building.
How about that? A modern building whose basement floor is empty but for an aqueduct ruin. Doesn't it look a bit different from the previous Roman aqueduct? That’s because it was built 1400 years later!
You are actually looking at the "Aqueduct de Médicis", built under Marie de Médicis or Maria de' Medici if, like her, you’re from Italy. Feel free to read all the text on the window if you speak French, but don’t worry, I’ll go over this later in a more secret location.
Marie de Médicis had an interesting life: her husband, King Henri IV, got stabbed in his carriage near Châtelet-Les Halles, as he was finally preparing her formal welcome as the new queen of France, years after they had already been married. After Henri’s death, Marie became the regent of the kingdom, because her son, Louis XIII, was too young to rule.
Marie's relationship with her son Louis XIII was rather tumultuous. At one point, they even went to war against each other. And I don't mean a family feud, I mean a literal war, with allies, armies and such. He jailed her in a castle, but she did a bit a swashbuckling and escaped through a window using a rope ladder - at the age of 41! So yeah, she had an incredible life, but she was trashed in French history books, like most powerful women of foreign origin.
So did Marie de Médicis just replace the Roman aqueduct? Not really, she copied the path of the Roman aqueduct but built her own structures. As you can see, it’s a bit fancier. Belgrand did the same thing a couple of centuries later, sometimes he even built his aqueduct directly on top of the Médicis aqueduct, which makes for a very weird-looking bridge in the town of Arcueil.
OK, I don’t know about you, but the whole point of walking through Paris is not to look at window displays, but to see the actual old stone from up close, so let’s find some. The sun is still super strong for me, so let’s find some shade on the way. So walk back down the street the way you just came, keep Parc Montsouris to your right and turn left onto the tree platform. I'll meet you in the centre, off the paved path and between the trees.