The decorative arts are housed in the Lacroix-Laval mansion by Soufflot (architect of Paris’ Panthéon). Among the furniture and objets d’art is a five-octave harpsichord by Donzelague, the 18th-century creator of musical instruments. The collection next door in the l’Hôtel de Villeroy takes you through 2,000 years of priceless fabrics from around the world. Look for the partridge-motif brocade from Marie Antoinette’s bedchamber and a 150-color brocaded satin woven for Queen Victoria.