“Porte” means “door” or “gate” in French, so we name the squares from which you enter or exit the city. There are 58 “portes” in total all along Paris’s geographic perimeter. Montreuil, Vanves, Saint-Ouen are the names of the villages/suburbs which are still outside the city limits... but maybe not for long as our politicians are working on the project

“le Grand Paris” where they will extend the city limits to include at least the close suburbs (other projects plan to extend the limits of Paris to as far as Rouen in Normandy or even to Le Havre and I'm not kidding!)