Best cities in Italy for runners?

Hey all - planning on spending 2 months in Italy this April/May and have not decided on what city/cities I'm going to make my headquarters (planning on 3 weeks in one spot, 1 week of travel around Italy, then repeat). I'm a big long distance runner and would love to be in a city that is great for runners - in terms of having a variety of routes available, pretty scenery (i.e. runs along a river or lake), options for mixed elevation (some flat routes), etc. Any thoughts? I studied in Rome in college and don't remember a ton about the running culture there.

Also - on a similar note, are any runners out there aware of any cultural norms that vary with respect to running in Italy vs. the States? i.e. I have heard some say that in some cities you could be fined for running shirtless, whereas it's very common in the States (unless you are going into a store for example)