The zone of production extends into the communes of Barolo, Castiglione Falletto, Serralunga d'Alba and parts of the communes of Cherasco, Diano d'Alba, Grinzane Cavour, La Morra, Monforte d'Alba, Novello, Roddi, Verduno, all in the province of Cuneo, south-west of Alba. Although production codes have always stipulated that vineyards must be located on hillsides, the most recent revision of the production code released in 2010 goes further, categorically excluding valley floors, humid and flat areas, areas without sufficient sunlight, and areas with full-on northern exposures.