Don and Peggy wanted to see the Louvre, one of the world's finest collections of art. In the courtyard of the Louvre they built a huge auditorium -- underground, so as not to disturb the view. The glass pyramid domes the auditorium.
We also toured one of Paris' smaller collections, the Museum of the Middle Ages at the Cluny gallery, built on the site of an ancient Roman bath. The castle dates mostly from the 15th century. See the little stone animals craning their necks out as if to protect the house? They are actually downspouts, carrying rainwater from the roof away from the building so as not to erode the stone walls and decorations.