I have discussed these areas in other threads, but this time I want to make my question absolutely specific. Before that, I should clarify that my interest in Tivoli would obviously be to see Hadrian's Villa and Villa d'Este, not so much the city itself.
Anyway, I have never visited any of these places, and I have a day to visit just one of them. Let's assume it doesn't matter where I'm starting or finishing or how long I will have to be on a bus or train or any of that. Let's just imagine that I will have ten hours at the place of my choice to see the sights, explore, grab lunch, etc.
Which is best? I appreciate any advice on this, thanks.