"This 17th-century townhouse tucked within a lost-in-time pocket of Saint-Germain-des-Prés is like a secret sanctuary; the fact that it sits on the remains of a 13th-century abbey adds to the mystique. For the 48 rooms and public lounges, interior designer Laura Gonzalez tapped into a coterie of master French brands—chandeliers from Dedar for Hermès, wallpaper from Ananbô, fabrics from Pierre Frey and Le Manach, and vintage furniture from the flea market Les Puces de Saint-Ouen—to conjure Left Bank romanticism. Eye-catching objets and artwork stippled throughout give the feel of heirlooms passed down through the generations. Perk: A leafy interior courtyard is ideal for cocktails or just alfresco lounging with a book."