Leaving Badia a Passignano, you continue through the woods to the bottom of the valley in the direction of San Donato in Poggio, one of the main stopping points of the Sanese. The village preserves its medieval urban structure intact; outside the walls, there is the parish church of San Donato, which maintains the original architectural features and is one of the most important examples of Romanesque architecture in the Florentine countryside. After passing Madonna di Pietracupa and the Ricavo estate, you reach Castellina in Chianti where, before entering the historic town center, you find the Tumulo di Montecalvario, an imposing Etruscan sepulchral monument built at the end of the 7th Century B.C. Located in a strategic position on the ridge overlooking the Valdelsa and the surrounding areas, Castellina was an outpost of the Republic of Florence and, in the 15th Century, was equipped with powerful defensive works based on the projects by Giuliano da Sangallo and Filippo Brunelleschi. In the historic town center you find the Rocca, today seat of the Museo Archeologico del Chianti, the church of San Salvatore, restructured in neo-Romanesque style, the Via delle Volte, a charming, covered pedestrian passage. For centuries, the village has been an important stopping point on the way to Rome, on the border between the Sienese and Florentine sides.