Palazzo dei Mercanti is one of the buildings that gives central Piacenza its mercantile character. Set near the heart of the old town, it recalls the city's role as a trading and administrative centre on the Po plain, where Lombard, Emilian, and river routes met.
You do not need a long visit; the point is to notice how the palace sits with the surrounding squares, arcades, churches, and civic buildings. Piacenza rewards this kind of close looking, especially if you are breaking a journey between Milan, Parma, and Bologna.