The remains of the Abbey are located near Chiusdino, between Siena and Massa Marittima: the Abbey was home to one of the most important Tuscan monasteries. Galgano Guidotti, after taking the Cistercian habit, had a chapel built on Mount Siepi, where he then chose to die as a hermit. The Cistercian monks later built an oratory and a building in honor of the monk, who later became a saint. Today the Abbey is considered one of the most important works of Gothic-Cistercian architecture in Italy.