Piazza Gae Aulenti is worth passing through for a few pics when in Porta Nuova. Why not live the cultural experience and visit the museums, art galleries, and cathedral in the area— your sightseeing tour starts here. Milan has lots of other big landmarks you might want to see such as Cathedral of Milan.
If you want to give your credit card some exercise, head out to Corso Como in Porta Garibaldi. Hotels.com travelers also like the cathedral, museums, and art galleries in the area. Splash some more cash at 10 Corso Como, Armani Megastore, and Milan Fashion District.