The walnut, originally from the East and introduced in Europe by the Romans, becomes the main culture of the Dauphiné region in the 19th century. In 1938, this production is protected and recognised thanks to the Controlled Designatin of Origin (CDO) Walnut from Grenoble (French equivalent for Protected Designation of Origin). This designation establishes precise specifications to be applied to the walnut production in order to guarantee a high quality product. The geographic area of the CDO goes from Chambéry (Savoie) until Romans sur Isère, in the Drôme hills. Today, 20% of the Grenoble Walnut producers are in the Drôme, which represents 17% of the territory of the registered designation of origin.