The medieval castle of Soiano was built on a Roman site in the 10th. century as a defense against the constant plundering and invasions of time. It was rebuilt several times and served in the Middle Ages as a seat of local families to elect consulates and administer justice. The well-preserved wall shows traces of the former battlements and the former drawbridge system. A tower, converted into a bell tower in the 17th century, guarded the entrance that led to a courtyard that was used to accommodate the fleeing population. Two more defensive towers are still preserved today, of which the northernmost is better preserved. In modern times, another gate was added to ward off possible attacks by the Savoy troops. The castle of Soiano was also a meeting place for the family councils of Chizzoline and Soiano, and is now owned by the municipality.