Compared to the Duomo square, this one is pretty quiet and peaceful. Good for a quick stroll and a few pictures of the fountain and the surroundings.
A terrorist attack took place here in 1969, when a bomb went off, killing 17 people and wounding 88.
It's right next to Piazza Fontana tram station, lines 24 and 27. You can also easily get here from the Duomo Square.
Wikipedia https://en.wikipedia.org/wiki/Piazza_Fontana_bombing
Address Piazza Fontana, 20122 Milan, Italy
Coordinates 45°27'48.634" N 9°11'37.438" E