We were enjoying our lunch under the shady arcade in Villeneuve-sur-Lot when someone said "That's odd." Looking at the building on the other side of the square, we noticed the unusual roof line. It slopes up to a point at the back left corner. We asked our waiter if he knew the reason for this. He said he'd never even noticed it before! Duh! We puzzled over possible explanations, but couldn't come up with anything that sounded reasonable. Any ideas??