Galerie Vivienne, from 1823. Enter through the neoclassical stucco friezes and walk the marble-mosaic floors past esoteric boutiques, galleries, and antiquarian bookstores. The gallery makes a right-angle and drops to a lower section, all of it in the natural glow from skylights. Make it a passageway afternoon adventure by following the walking directions in the No Worries Paris guide. This is one of many and they all connect up. A good rainy day activity.