Chianti Classico is located precisely between Florence and Siena, extending across the municipalities of Radda, Gaiole, and Castellina. It lies at a higher altitude and is hillier than the larger Chianti zone, which is one of the key differences. With elevations of up to 700 meters above sea level, viticulture here has a significant advantage. The grapes receive ample sunlight, allowing them to ripen evenly. The large temperature differences between day and night slow down the ripening process, leading to more intense aromas.
Furthermore, the grapes preserve their acidity—maintaining their freshness. In the northwest, around San Casciano Val di Pesa, vineyards between 200 and 300 meters above sea level predominantly feature Galestro soils. This is a very poor, dry soil type made up of loose blue-gray marl. In the central and southern parts of the Chianti Classico region, Alberese soils prevail, which are poor substrates made of weathered sandstone.
Additionally, Chianti Classico has extra geographical units called UGAs (Unità Geografiche aggiuntive), which are equivalent in quality to a French "Cru." The eleven UGAs for Chianti Classico wines are:
- San Casciano
- Montefioralle
- Panzano
- San Donato in Poggio
- Castellina
- Vagliagli
- Greve
- Lamole
- Radda
- Gaiole
- Castelnuovo Berardenga