Thun Castle was built in the middle of the XIII century and was the seat of the powerful family of Thun, which in the valleys of Non and of Sole they possessed other prestigious residences. The castle is situated at the top of a hill at 609 m, close to the village of Vigo Ton in beautiful panoramic position.
It is an example of the more interesting architecture of the trentian castles, the civil-military structure is typical of the gothic style and is surrounded by a complex system of fortifications formed by towers, lunar bastions, a moat and a rampart; the imposing "spanish door" (1566) was constructed with massive ashlar stone arranged in a radial pattern. The fortifications are central with a square plan with strong ramparts for defense with firearms, four square towers at the corners and, after the moat, another wall with deep splayed slits and two medieval towers.Passing the gate of the drawbridge (1541) and passing the first courtyard, which is in turn becomes the path on the northern side by a long colonnade, formed by eighteen mighty stone columns, which meets the entrance of the count's palazzo. The public rooms were located on the ground floor, while on the first floor were the bedrooms of the lords. Among the numerous rooms that are still richly furnished, the most valuable is the "bishop's room", entirely coated with pinewood, with a coffered ceiling and a monumental door (1574), inhabited by the prince-bishop Sigismondo Alfonso Thun