Where to go between Venice and Rome

We really like Bologna, which is right on the main train line between Venice and Rome. Lots of pre-Roman, Roman, and medieval history there, which is summarized on the University website thus:

https://www.unibo.it/en/university/who-we-are/our-history/bologna-art-and-history

The main church, San Petronio, is interesting in that it has a medicinal line built into the floor, which played a major role in 17th century science—-including confirmation of Galileo’s controversial theory that the earth orbits around the sun.

https://pauls-bologna.blog/2017/11/02/the-meridian-line-of-san-petronio/

The public library, on the same piazza as the church, has Roman ruins you can tour under the main floor:

https://www.atlasobscura.com/places/salaborsa-library-roman-ruins

The clock tower is also well worth a visit:

https://www.emiliaromagnawelcome.com/en/activities/300685/visit-to-the-clock-tower-torre-dell-orologio-and-to-the-municipal-art-collections

The University of Bologna has a number of interesting museums you can visit; pay attention to the hours as they can be irregular.

https://sma.unibo.it/en/university-museum-network

And if you are interested in the history of music, you might like the Music Museum and Library as much as we did:

https://www.bolognawelcome.com/en/places/museums-and-private-collections/museo-internazionale-e-biblioteca-della-musica-2

I would second the suggestion for Bologna and add in another option, Padova. We just spent 5 days in Padova and enjoyed it immensely. The Scrovegni Chapel is wonderful as is the adjoining Civic Museum. It is a university city so lots of young people, interesting sights, beautiful squares, and good food.

Five nights in Venice is lovely and not at all too many --- there is so much to see beyond the famous sites, and just being there is an experience like no other in the world.

Hard to beat Orvieto, but if you are looking for a smaller town instead of a city like Bologna (which we also love and have spent about 3 weeks total there), check out Ferrara. It's an hour by train from Venice and you can daytrip to Bologna in half an hour. Very walkable and a lot of residents ride bikes around, too. Still has most of its surrounding walls and you can walk on them like you can in Lucca: https://www.travelemiliaromagna.it/en/walls-of-ferrara/, Also there are walking paths just outside them. Kind of a long train ride from Ferrara to Rome, but it wouldn't be too hard to take the train to Orvieto (3.5 hours), store your luggage, spend the rest of the day in Orvieto, and then train to Rome in 1.5 hours. I wouldn't think Ferrara would be at all crowded in March --- we were just there in December and despite the big Christmas market, it was not crowded and we visited several places where we were by ourselves. Good food in Ferrara, too: https://iviaggidiraffaella.blogspot.com/search?q=Ferrara

Thanks for all of the great suggestions!

I would spend the 4 nights in Padua but take a day trip to Vicenza, home of architect Andrea Palladio. His work is impressive, especially the Teatro Olimpico. We did a self-guided walking tour. If you decide on Padua, it's never too early to make reservations for the frescoes by Giotto in the Scrovegni Chapel - from 1303–05 and the vast 13th-century Basilica of St. Anthony. At the center of the historical city, the buildings of Palazzo del Bò, the center of the University of Padua. Pre-book a tour focusing on the Palace's twentieth century additions (Palazzo Bo e il '900 di Gio Ponti) is available on Saturdays, Sundays, and observed holidays. On these days, visitors can visit the courtyards (and the works of art on display there), the Rectorate (il Rettorato), the Old Archive (l'Archivio Antico), as well as the "Anatomical Kitchen" and the Anatomical Theatre. Furthermore, the Basilica, the Galileo Galilei Great Hall (l'Aula Magna Galileo Galilei), the Hall of Forty (Sala dei Quaranta), and the Hall of Medicine (Sala di Medicina) will be open to visitors.

Walk in the steps of Galileo! And the Anatomical Theater is amazing. I would have added the link but I couldn't get it to switch to English. The Botanical Gardens and enjoying time in the main square should fill up your 4 days.

I have been to Padova as part of the RS Village Italy tour (my one and only RS tour!) and even went a couple of days early to explore on my own. I would like to return eventually with my husband as part of a future northern Italy only trip.

For this trip, I'm thinking of adding a couple of nights to the itinerary:
5 nights Venice
3 nights either Bologna or Ferrara
3 nights Orvieto, or?
5 nights Rome

Thanks again for the feedback and resources!

I should have mentioned Ferrara as well as Bologna. Smaller, quieter, fewer tourists. It is a UNESCO Heritage site with treasures of its own, such as the wonderful frescoes in the Salone dei Mesi in Palazzo Schifanoia. And is only 35-40 minutes by train from Bologna should you want to see some of the attractions I mentioned previously on a daytrip.

One of our favorite hotels in all Italy is Hotel Annunziata in Ferrara. Our room had a view of the castle across the little piazza. Zeno’s mother kindly retrieved my day bag that I carelessly left in a restaurant the night before, on a day when the restaurant was closed (the owner is a friend of hers).

https://www.annunziata.it/en/

https://www.ferraraterraeacqua.it/en/renaissance/the-wonders-of-este-art

https://www.ferraradeltapo-patrimoniomondiale.it/en/

Go to Bologna. You will love their wonderful old-world arcades that are everywhere. Visit Ferrara and Parma if they strike your fancy. Stay on Via Bertieri or Via Oberdan. The restaurants are unsurpassed, and I'm a vegetarian. For a comprehensive Etruscan immersion in a lovely old-world museum setting try the evocative and surprisingly vast Museo Archeologico. 7 hours might not be enough.

Lola and Cherryplanter, thank you for the great suggestions! We are still deciding between Bologna and Ferrara. I've also reversed the itinerary to start in Rome and end in Venice (better flights/price). Essentially, we have 16 nights. If we spend 5 each in Rome and Venice, I'm still trying to figure out the remaining 6 and am leaning heavily toward Orvieto for 3 of them.

*Update: We decided to spend a week in Cortona and rent a car to explore the surrounding towns and villages.
5 nights Rome
7 nights Cortona
4 nights Venice

Thanks again for the suggestions and feedback!