The Navigli area of Milan is vibrant. It is a canal surrounded by restaurants, bars and cafes. There are foot bridges to get from one side to the other. It is very pretty and fun.
New built area of Milan city, but historical architecture is protected. This area has nice buildings, shopping and entertainment center, park. Also, there are quite nice residency buildings.
The square in front of the station is always very lively and there are several very beautiful buildings around - the main station, Hotel Galia, the Pirelli skyscraper. Although there are vagrants and homeless people, it does look safe.