Traveling to Italy this fall...

Florence makes more sense when also visiting Rome and Venice. You could stay outside of Florence in a Tuscan town and do Florence as a day trip.

What would the girls like to see and do? Let them plan a few days. Hit your local library for guidebooks and travel DVDs. Review them together. Given the range of options for Florence and surrounding area, Florence would be a better choice.

As mentioned, Florence makes sense geographically. And its wealth of museums means going to even a couple means you’ll have seen a lot of really significant art, which may be enough for all of you.

Way south of Rome, our one day in Naples was part of a stay in Sorrento, where we visited Pompeii and other places on other days. Besides pizza, where Naples is considered its birthplace, there’s one really superior museum, which holds much of the surviving art and artifacts from Pompeii. The National Archeological Museum in Naples also has an “ancient erotic art” room, which might not be a part you’d want to include with your daughters.

Florence has a large number of American study abroad students. Your daughters may enjoy encountering and talking with them about their experience. Gustapizza near Piazza Santo Spirito in Oltrarno would be a good spot for that, plus they serve really good and fairly inexpensive Naples style pizza. Something different from just more museums, and another good reason to visit Florence.

sara,

I agree with the others, Florence would be the logical choice since it's "on the way" to Rome, especially with such a short time frame. That's the classic V/F/R route used by Rick Steves tours and others. There are many interesting sites in Florence and if you get bored with too many museums or whatever, take a day trip to Siena, Lucca or other nearby towns.

You'll only have a few days in each spot so plan your touring carefully so you don't waste any time. I assume you're using open jaw flights, inbound Venice and outbound Rome?

Agree with Suki; we stayed at a Tuscan Villa and visited a few lovely Tuscan Villages as well as Florence. You'll have to rent a car as it's the easiest way to see Tuscany. When going to Florence, park at the train station; it's a short walk to the Duomo. 3 nights in Venice; 4 nights Rome; & 5 in Tuscany (this time); come back for more. Train it from Venice to Florence; rent car, tour Tuscany then drop off the car in a suburb of Rome & taxi to your accommodation or train it from Florence. You'll need an Int'l. drivers permit obtained at AAA.

Remember to pre-book any museums or points of interest asap so you won't have to line up or be disappointed not to get in.
Good Luck,
Jean

Our sons are in their 30s. When they were teenagers we did the same trip as you're planning.
We did Venice, Florence and Rome.

We did a side-trip to Pisa and that was such an icon that the entire family enjoyed it. We didn't allow enough time for that trip.

In Rome, the Capuchin Crypt was a good visit for all.

I'm planning a trip to Italy for next spring (maybe one this fall, also) and am looking for unique things.
I've found several Thermal Spas, some of which may fit into our touring plans.
start watching this at the 5:21 mark
https://www.youtube.com/watch?v=ioQbos5qSYw

There are several in Tuscany. They just may not be in your path.

If you fly into Naples and out of Venice (or vice versa), then Naples is just as convenient as Florence. Which place do you think they would find most compelling? Why not have them flip through a guide book and pick which is most interesting to them?
I thin it should be a matter of personal preference, but I consider Naples to have more outdoor/large scale sites of interest--of course Pompeii and Herculaneum but also Naples Underground, castles/palaces, on and on. I find those more invigorating than a museum unless there is something very specific I wish to see or learn about in a museum.

I would never recommend beginning in Naples on a first trip to Italy. Venice is the best place to start because it's low key, easy to just soak it all in while getting over jetlag.

Frank mentioned the students in Florence. You may want to consider Bologna instead. It is a university town, with lots of foreign students including many Americans. It doesn't have the wonderful art and architecture of Florence but that may not interest your teens. You can tour the oldest university in Italy (Europe?), and day trip to other towns by train (Florence, Modena, Parma, Padua, Ferrara). Added bonus - many fewer tourists than Florence and cheaper prices.