However, the castle experienced a tragedy, because, at the beginning of the fourteenth century, suffered a violent siege conducted by Siena which caused serious damage resulting in unavailability. This siege had led to the abandonment of the settlement for the benefit of Montiano village, which had begun to develop only from the late thirteenth century onwards.

The old Montiano Castle is located in the greenery and is presented in the form of ruins.

the remains of the walls are well recognizable that surrounded the entire fortified settlement, developing along a perimeter of elliptical shape; Also visible are the ruins of other structures not readily identifiable.

The complex was built entirely of sandstone, as demonstrated by the ruins that have been preserved.