Piazza del Popolo was once called the Market Square location because of the market since the Middle Ages. The central part was occupied by the commercial port remained active until 1875; marble slabs indicate its former location. Here is the seat of the old Palace of Justice, improperly called Broletto, built by the Visconti in '300 - '400, with a six Gothic arches Porch. On the front there are terra-cotta medallions with busts of the Visconti and Sforza families. In the time it was the seat of the Bargello and prisons. Overlooking the square is the church of Santa Maria di Loreto and Santa Marta erected in 1592 by Frederick Borromeo.