Here a couple of suggestions. I have put together for those who have a limited time in Rome and want to see as much they can on a guided tour!
Vatican museums (Sixtine Chapel), St. Peter's basilica, Colosseum, Forum
Trevi Fountain, Colonna Square, Pantheon| Ghetto, Teatro di Marcello, Capitol Square, Forum, Colosseum
One should always try to dedicate more than one day to any of the world’s great cities, Florence included. With this premise, if you’ve got to do it, I will help you choose what to see so that you make the most out of your limited time.
We can catch the train in Rome and in 1h20 we will be there!
Starting from St. Maria Novella station we will walk up to the famous Duomo with Brunelleschi’s cupola, Giotto’s Bell Tower and the Baptistery. Nearby we will visit the Accademia with Michelangelo’s David (reservation in advance).
Strolling down via Roma we will find ourselves in Piazza della Signoria in front of Palazzo Vecchio, the city’s seat of government with an incredible outdoors statues setting. The David out there is a cop.
We will walk then to the end of the Uffizi buildings (no time to visit them) to the Arno and catch a view of the river and the Ponte Vecchio.
On the way back to the station, we will go to via Tornabuoni – the luxury shopping street – and hop into the church of Santa Trinita where you’ll be rewarded by a beautiful fresco by Ghirlandaio. Look carefully at the backgrounds of each scene as you should recognize some of these locations – we’ve seen them together!
It is possible to go to Florence from Rome by train (1hour 20 minutes) in order to spend a day there and come back in the late afternoon.