The municipality covers an area of less than 50km2, between the north-west slopes of the volcanic massif of Monte Amiata and a section of the Val d'Orcia, the point at which creeps from the province of Siena towards that of Grosseto.
With the exception of units of low hill near the beds of rivers, the region extends mainly in hilly and mountainous odds, but good exposure allows the cultivation of a species of olive, Olivastra Seggianese, called up to elevations of low mountains, managing to produce an oil of excellent quality.