The site consists of the hermitage said "Rotonda of Montesiepi" and the great Abbey, now completely ruined. St. Galgano, owner of the place, we know that he died in 1181 and who converted after a disorderly youth, retired to life as a hermit: Galgano was driven into the ground his sword, in order to turn the weapon in a cross. Even today, you can see the rock from whose cracks emerge and the hilt of a sword segment. Obvious analogy with the Arthurian myth raises curiosity and speculation about possible relationships between the mythology of the Round Table and the history of the Saint from Chiusdino. In place of his death it was first built a chapel and, in 1218, work began on the construction of the Abbey. His monks had considerable economic and cultural importance in Republic of Siena, but in the first half of the eighteenth century the complex appeared almost collapsed. In 1924 it began the restoration by Gino Chierici. The Church is oriented east and has a gabled facade. Admission is entrusted by three portals with round arches, the main entrance is decorated with a frieze of acanthus leaves. The aisles are open to single and the left side are placed a small spiral staircase and the doorway leading into the cemetery. Maximum architectural work is the apse. To the right was developed cloister, around which revolved the whole life of the Abbey. The interior, now without cover and floor, is a Latin cross, divided longitudinally into three naves by piers. From the right transept it leads to the sacristy; southern end it was the Scriptorium, where monks copied manuscripts. It is a very large room divided into two naves covered by cross vaults decorated with spirals. The picturesque site of the Abbey was used as the setting for several films, among them "The English Patient", by Anthony Minghella (1996).