Definitely the Sammezzano castle is on top of my list. Situated in Tuscany (near Florence) its owner had a crush for oriental culture. Thus, he decided to build this very peculiar castle in which each room follows a different arabic or middle-eastern architectural style. Pictures and more history here: https://www.homeinitaly.com/magazine/post.php?post_id=176.

Unfortunately it is privately owned and its kinda hard to register for a visit.