Built in an unspecified period by the Benedictine monks of Santo Stefano, the building is only half complete. In fact, only the western portion is visible and in good condition. A third independent quadrangular tower is surmounted by two pointed turrets.

Since the structure was mainly agricultural and defensive and not military, Federico Borromeo in the sixteenth century encouraged the channeling of water and the reclamation of marshes.

It is interesting to note that the cultivation of rice was only allowed in places suited to the geological conformation, and it was forbidden to transform the meadows into rice fields in order to safeguard the vineyards and mulberry trees for the cultivation of silkworms.