Did you know that although chateau is the French word for "castle", when referencing wine, a chateau refers to "wine estate" or "vineyard". The name is most commonly used in France's Bordeaux region. The French only allow the word chateau to appear on a label name when an authentic vineyard with the traditional use of the name has produced the wine. The only exception is when the word chateau is an essential part of the name, such as Chateau-Challon, or when it's an American winery, such as Chateau St. Jean.