If you look left, you'll get a better view of some of the beautiful houses you just walked by. At the corner of rue Georges-Braque and rue Nansouty, opposite number 14 bis, you can see the very tall and square Villa Guggenbühl, with its uniquely pierced roof over the terrace.
I like to think of it as the mirror image of Le Corbusier's Ozenfant house. First, because it was designed by a French modernist architect, André Lurçat, for a Swiss painter, Walter Guggenbühl, in 1926. Then because Lurçat did not have fascist but rather communist leanings. When he worked on the reconstruction of the French city of Maubeuge, which had been 80% destroyed by Nazi bombs, he took the opportunity to make the ground level more equal between the various parts of the town to promote equality between various neighborhoods. He insisted on keeping some of the historical buildings that had survived the bombings and involved the inhabitants in deciding how the new city should be designed, something I wish more architects did in the 1900s.
Anyway, keep the park fence to your right as you go down the street, and keep following it as the pavement turns right. At that corner, you'll even get a last glimpse of the réservoir de Montsouris to your left - yes, it's that big. In the distance you'll also see another Wallace fountain, this one with a special feature: you need to press on a button to get water.
We still won't go into the park right now, but it’s a nice place for a drink or to just lie down on the grass after the walk. Just keep walking along the fence as the pavement turns right.