Do not miss going through the Galleria Vittorio Emanuelle. This square hosts one of the temples of opera, La Scala, I had to look for it, having expected a more ostentatious building. Here also is Leonardo!
Cordusio Square is near the center of Milan and from it you can see some of the city's most important monuments, such as the Duomo and Sforzcesco Castle plus several boutiques. A few meters away is the headquarters of the Milan Stock Exchange and the Chamber of Commerce.