Hi Paige!! Welcome to WeddingWire!! Honestly, you could go anywhere in Italy and be inundated with history. Rome, of course, has Vatican City and all of the history of the Romans. I've never been, but I hear it's amazing.
Florence is amazing. History beyond belief and just beautiful in general. Definitely try to get into the Palazzo Vecchio, I think, is an amazing art museum. I recognized half of the art there and it was stuff that I was never really convinced existed until I saw it. Michelangelo's David is also somewhere in Florence, if I remember correctly, and that was cool.
Venice might be getting cold around that time of year, but I think it's worth visiting for a little bit. Walk around and go inside St Mark's, it's eerie but really cool.
I have not honeymooned yet, but I spent a lot of time in Italy during a study abroad! I mimic what Maggie said, Florence is incredible! The David was even more amazing than I imagined, and I also loved Florence in general. In Rome, you have the Vatican (incredible - I’d recommend a guided tour to hit the “high points” if you don’t have four days to see it), the Sistine Chapel (also a must!!!), St. Peter’s Basilica, the Colosseum, the Pantheon, the Roman Forum, the Spanish Steps, Trevi Fountain, Imperial Forums, and so much more. If you do go to Venice, I would not plan for more than 6-8 hours there. It is not as interesting as I anticipated (though a honeymoon gondola ride would be romantic!). Pisa is worth a day trip if you have time - I really enjoyed it! Same with Pompei. It was interesting/eerie. I honestly would recommend either of those over Venice if you’re forced to choose. Siena was also a really neat town worth a visit (and close to Florence if you go there). Y’all will have so much fun regardless!
Not a honeymoon, but I just spent a good chunk of my summer in Italy!
Rome is fantastic for history. I would suggest doing skip the line tours even if you don’t love tours, it could take hours off of waiting in lines.
I also spent time in Venice. If you go there, you HAVE to take a water bus out to the islands. My favorite is Burano, it’s all rainbow colored buildings ☺️
I spent about a day in Florence, which was my favorite. I wish I’d had more time to explore there, but I would highly recommend it! And a museum ticket includes just about every major attraction in the main part of the city.