IT'S one of the most prized vineyard sites in Tuscany, evocatively known as conca d'oro - or golden shell - with its south-facing slopes perfectly formed and framed by its natural amphitheatre shape. At its hill's crest, old stone buildings, including the majestic 11th-century Panzano castle, are a reminder of the area's history and its ancient dirt.

And that free-draining soil, called galestro, a friable schist-based compound of marl and clay, is scattered throughout Tuscany, especially the Chianti region, wedged between Florence in the north and Siena in south. However, conca d'oro stands alone because it's mostly galestro. And that suits sangiovese perfectly.

Giovanni Manetti in his Fontodi vineyards in the heart of Chianti. Credit:Jane Faulkner

It's one of the reasons, explains Fontodi winemaker-owner Giovanni Manetti, why his flagship wine, Flaccianello della Pieve, has always been a 100 per cent sangiovese sourced from the best parcels off the conca d'oro vineyards his family have owned since 1968. Yet, Fontodi's Chianti Classico is also 100 per cent sangiovese - although Italian wine law permits 20 per cent of other red grapes to be added.

''Panzano is regarded as the heart of Chianti, admired for centuries for its vines, and this parcel of land is right in the middle. It's made for sangiovese,'' Manetti says. ''There's lots of light; it's cooler between 450 to 520 metres; and it really has a unique microclimate with its galestro soils, so it's dry and not so fertile and the vines' roots go down deeply. That's why the flavours of the territory come out in the wine.''