Concierge.com's insider take:
Some of Tuscany's most essential landscapes, cultural attractions, and wines are concentrated in the province of Siena. The town itself has plenty to offer, but it's worth spending at least a day exploring the surrounding countryside. North of the city, in the Chianti Classico wine zone, thickly wooded hills alternate with perfectly manicured vineyards. To the northwest, the Val d'Elsa embraces tiny Monteriggioni, a perfectly preserved walled city, and medieval San Gimignano, with its surreal skyline of towers and wealth of early Renaissance art. To the southwest, in the wild, remote Val di Merse, you'll find the mystical, roofless 13th-century Cistercian abbey of San Galgano, whose majestic interior is now paved with grass. Europe's only real "sword in a stone" is on display in the nearby chapel, miraculously plunged into the rock, so the story goes, by former warrior San Galgano when he renounced the secular life. Immediately to the southeast of the city, the landscape of the Crete Senesi, bare clay hills furrowed with gullies and ravines, is most dramatic around the 14th-century Abbey of Monte Oliveto Maggiore near Asciano. In the abbey's cloister, don't miss the cycle of Renaissance frescoes depicting the life of St. Benedict by Luca Signorelli and Il Sodoma. Nearby, San Giovanni d'Asso is the home of Italy's only Truffle Museum (39-0577-803-268; www.museodeltartufo.it; open weekends only) and hosts the Festival of the White Truffle for two weeks in November. Head farther south down the SS2 Cassia road to find one of the most beautiful and iconic Tuscan landscapes of all: the Val d'Orcia, with its wide-open vistas and snaking lines of cypress trees. It's bordered to the north by the hill towns of Montepulciano and Pienza, while lofty Montalcino—perched high above the vineyards that turn out one of Tuscany's most famous red wines, Brunello di Montalcino—lies just to the west.