Spend an afternoon strolling around the perfectly manicured grounds of Parc Longchamp. Admire the collection of plant species, see if you can spot some wildlife or simply relax on the grass.
When you've spent a bit of time at this showcase of plants in 4th Arrondissement, why not make your way to Notre-Dame de la Garde, Chateau d'If, and La Vieille Charite? They're close to Parc Longchamp and also popular with many travelers.