Near Castiglione is the Castle of Buriano mentioned in the 10th century as belonging to the powerful local Lambardi family. 4 kilometres from the town is the Romitorio (hermitage) built in 1597 by Father Giovanni of Batignano on the spot where the Madonna had appeared to S.Guglielmo, who had taken refuge here before founding the Monastery of Malavalle. Every year on the second Sunday after Easter in honour of the saint a procession leaves the town to reach the "Romitorio".
The castle overlooks the northern part of the Grossetan plain and the ancient Prile from a high ground. It's completely restored, enough that its original plant is hardly recognizable.
From the Romanic period it remains part of the S. Maria in Arcione church, outside the castle, which has been rehandled in following times on the left side because of some collapses. The rock is a poligonal complex of buildings with fortified fence and internal courtyard, located at the top of the hill. The rock was organized in two floors and the entrance was through a door wich lead to a cross vault entrance way. From the rock you overlook the whole area from Vetulonia, Sestinga to Roselle.
Coming up from the valley some buildings installed on ancient quadrangular towers, belonging to the external walls of the castle, along the lower floor, are visible from the road.