At 650 m asl, not far from St. Casciano, there is the castle of Fighine. During the Middle Ages, its importance was given by its strategic position. In effect, it is set between the Valle del Paglia and the Val di Chiana and it immediately appeared as an important military complex for the control over the two areas.

As for the dating of the building there is not any certainty, but some documents report that the Castle of Fighine could have been built even around the mid-XI century.
The name "Fighine" was first quoted in a decree written by the Marquis Gottifredo who probably was a nobleman of Lombard origins. The document dates back to 1058 and it informs about the existence of a parish dedicated to St. Maria "de Fighine".
In the XII century, the Castle of Fighine was acquired as a feud by the Viscounts of Campiglia who also extended their power into St. Casciano and Celle sul Rigo. The first reliable document talking about the stronghold dates to 1266. It is an imperial diploma written by Frederick II who confirmed the possession to Tancredi di Campiglia. The concession to the Viscontis was later reiterated by Ludovico IV.
Anyway, the position of the stronghold had always attracted commanders of mercenary troops, local noblemen and the newly free towns. During the years, the city of Cortona first and then the aristocratic Paolo Orsini, member of a family having Roman origins, and finally Baldaccio d'Anghiari, leader of mercenaries, got possession of it. The latter, who died in 1441, bequeathed the Castle of Fighine to the Republic of Siena.
The people of Siena started the resettlement and reinforcement works of this building in 1446 but the works were abruptly interrupted by the papal troops who occupied Fighine in 1451. Only twelve years later, Pius II returned the fortress to the Republic. At the half of the XVI century, the complex was included in the estate of the Tuscan Grand Duchy. The period of peace and stability under the Medicis progressively diminished the importance of the Castle of Fighine, but at the end of the Middle Ages it was so powerful and admired that it was even compared to Orvieto in the documents of the town historical archive!
The castle still has its quadrangular original structure topped by tree towers and it houses the Church of St. Michael the Archangel on the inside. It is a building with a rectangular plan and characterized by a medieval architecture, as indicated by the East-facing apse which was customary in the period when it was built. Today it has three altars but they might have been five in the past. Inside the church, some paintings of the Orvieto and Florence art schools can be admired. In particular, it is worth signalling the St. Michael the Archangel by Bonichi di Lucignano (1750) which is placed behind the high altar.