There is something about the Milan night sky. Maybe it's something about this particular latitude? No, because Nice and Monaco had the same beautiful blue sky late at night. Maybe it's the ocean air? No, Milan is quite a ways inland and no ocean breeze to speak of.

Maybe is the air quality? No, Milan reportedly has pretty bad air compared to Nice and Monaco. So pollutants are not making a difference here. Well then can someone lend a hand here and identify what's the key feature of Milan night sky that makes it such a brilliant blue? Any suggestions would be greatly appreciated. Thanks and enjoy the slide show...