The "Square des Batignolles" is a public garden in the 17th arrondissement. It has been designed as an English garden and it's a really a nice place to visit and the area around it called "Les Batignolles" is also a pleasant part of Paris to discover. The area looks like a kind of village with a little church and calm streets.
From there to the edge of the city limit there was, and partly still is, a huge unbuilt area that belonged to the National Train Company. It was there that the City had planned to build the Olympic Village if Paris had won the games for 2012 (which London did !). The place is now starting to be renovated an yet a new big garden has opened before apartments buildings will be built around it.