In Italy, there is the ENAC regulation that doesn't allow to fly over any city, group of people, street, ecc. is very restrictive. I suggest you to pay attention to those roules. I think is impossible to fly over a monument in the center of Florence or in Venice..Thanks good links.
I did contact some towns and Florence linked me to a permit application, with a 30 Euro fee. Apparently I can apply to fly over certain areas.
Not sure I will apply. Maybe best just to try to find launch and landing points outside the walls of these towns and orbit around them outside.
I'm new at this and a lot of times, I'd be content just to get high enough above foliage and trees to get better views and take panos, not try any fancy paths to record video.