The historical archives of San Salvatore Abbey at Mount Amiata keep evidence of two fortified places having existed close to Radicofani since as early as 1007: Senzano and Sassina. These two castles were situated on one of the variants of the pilgrim's road, known as "via Francigena", which ran along the valley of the River Orcia. They were part of the benefits entitled to the monks of Monte Amiata by Emperor Henry II - as confirmed twenty years later by Conrad II and in 1072 by Beatrice and Matilde of Tuscany, against claims by the Bishop of Chiusi and the Abbot of San Piero in Campo

     Later the two castles fell into disuse. In 1205 Abbot Rolando authorised their reconstruction to be carried out by some people from Radicofani, against a grant of one half of the relevant feudal rights. The agreement was reformulated in 1248 whereby also a few issues concerning the boundaries of the castle territories and the rights of other local owners were settled. In 1369 the monks of Amiata decided they were no longer prepared to refund the Lord of Radicofani for the salaries of ten warders in charge of the castle of Senzano, and so they gave permission for the two castles to be dismantled.

     Today there remain just a few hardly visible ruins of both castles: Senzano, on the rocky outcrop on the crest of a hill, and Sassina close to Casa al Treggia.