Fodor's Expert Review Hôtel de Châteaurenard
Across from a commercial gallery that calls itself the Petit Musée Cézanne (actually more of a tourist trap), this 17th-century mansion once hosted Louis XIV—and now houses government offices. This means that during business hours you can slip in and peek at the fabulous 18th-century stairwell, decorated in flamboyant trompe-l'oeil. Pseudo-stone putti and caryatids pop into three dimensions—as does the false balustrade that mirrors the real one in stone.