Passerino or Bonaccolsi Tower is the most ancient building currently existing in the palatial complex. The architectural structure is characterized by the typical Ghibelline crenellations (rebuilt around 1820), which demonstrate the original essentially defensive function of the building and, as many watch towers, it is perfectly aligned with the four points of the compass.
It is about thirty meters high and it is divided into five floors that must have been originally interconnected.
