Situated in strategic position of a hill in Valdichiana, the castle of Fighine is mentioned for the first time in a document dating back to 1058. In the 12th century it belonged to the Visconti family of Campiglia d`Orcia, who then extended their power over San Casciano dei Bagni. In the following centuries the castle was the object of numerous disputes involving local noble families. After having been occupied by the army of Cortona, the castle was given to the Orsini family. The Republic of Siena conquered it in 1441.

Between 1446 and 1451 the castle was enlarged and consolidated. The works were interrupted in 1451, due to the occupation by the Papal army. Siena re-conquered it only in 1463, and when the town was annexed to the Grand Duchy of Tuscany, the castle passed under the control of Cosimo de` Medici.

The square donjon features three angular towers: the so-called "old tower" has a square shape, is taller than the others and represents the most ancient part of the castle; a second tower has an octagonal shape; the third one has a half-octagonal shape. The old town walls still surround the hamlet. One of the round towers decorating the walls has been used as the apsis of the church of San Michele Arcangelo.