We have been to Italy before and will be in Rome, Bologna, Florence and Ferrara for a few weeks this December 2021 and early January. We are limited to public transportation. We have heard about Santa Severa, San Marino and La Scarzuola but would appreciate any thoughts on whether they are worth visiting or if there are other Castles or Experiences you suggest we could visit on a day trip from one of our base cities. We are all easy going adults who like to take our time and enjoy authentic food, architecture, non-touristy or unique experiences and castles. Thanks in advance
For Emilia-Romagna a good resource of details is the Youtube channel of the Region. There is a playlist dedicated to the castles and fortresses: https://www.youtube.com/watch?v=ypUjBICna80&list=PLthEcPx5GkGnEzKKtmbpdkNHDjLM0SdUk
Are divided by provinces and in each one you can find several ones. My favorites: Vignola, Fontanellato, Torrechiara, Carpi, San Leo, Ferrara, Vigoleno, Rivalta, Castell'Arquato.
If you have an interest in Byzantine mosaics, Ravenna should be visited.
We loved visiting the castle of Torrechiara by bus from Parma, especially the wild frescoes in many of the rooms, the kitchen, and the views.
A good friend of mine who lived in Friuli-Veneia Giulia recommended a daytrip to Monselice when we were visiting Ferrara. We never made it there but it is just a 40 minute train ride from Ferrara and there is a castle there and the small town looks quite interesting so I still have it on my wish list.