The Château de Fayolle looms large among the lush greenery that covers the rolling hillsides of the Dordogne region in France. The chateau is steeped in history, and it's now for sale. New owners will be delighted to discover some of the secrets the castle has to offer. But it also has a curious quirk that sets it apart from other castles in the region. See if you can guess what it is.