I am always banging on about the fact that Italy should do much more extensive research into the different terroirs in her wine regions in order to arrive at a system of subzones, or crus. But I merely have to mention this to be confronted with terror in the faces of whole swathes of wine producers keen to dispel the idea that some parts of their region could be better than others, fearing their vineyards may lie on the 'wrong' side of the quality line.
This is why even an area as extensive as Chianti Classico has avoided the concept...