Piazza Mercanti is a charming small square situated in the vicinity of Piazza Duomo. Overlooking the square are a group of buildings serving as a perfect example of Milanese architecture ranging from the Medieval ages to the 17th century. One of the more dominate buildings surrounding Piazza Mercanti is the 13th century Palazzo della Ragione which dates back to Milan’s communal age.  A few of the other significant buildings include: the elegant 14th century Loggia degli Osii which was commissioned by Matteo Visconti and decorated in black and white marble, the 15th century Casa dei Panigarola (Palace of Notaries) and  the 17th century Palazzo delle Scuole Palatine (Palace of the Palatine School) . Also near Piazza Mercanti at via Mercanti 2, you will find the 16th century Palazzo dei Giureconsulti; a building commissioned by Giovanni Angelo Medici, aka. Pope Pius IV. 
Piazza Mercanti
M1-M3 Duomo, M1 Cordusio