Florence surroundings: "Must-visit" Towns/Sights ?

San Gimignano is quite small; I think you could see something else that day if you can deal with the likely transportation issues. I know San G + Volterra is a common combination for day-trips. [Edited to add: I meant to say "one-day bus tours".]

Many people manage to cut their time in Lucca short enough to squeeze in a stop in Pisa to see the Leaning Tower. Many of us like Lucca considerably better and would suggest that you go to Lucca first and then make a decision about whether you want to leave early enough to go to Pisa on the way back to Florence. It doesn't appear that waiting until the last moment to buy the return ticket(s) will cost anything extra as long as you do not choose one of the relatively rare routings that includes some time on an Intercity train (which probably wouldn't save you any time, anyway).

I loved Siena, but one of the reasons I loved it was the walking tour guide I had who made the city come to life. A good guide book is a must. An audio guide is great. If you can find a walking tour with a live guide, though, I'd highly recommend it.

• Lucca

Give Pisa a miss unless you really want to see the tower.

i don't think you need 5 days for Florence, beautiful though it is.

We rented a car at the airport for one of our days in Florence. We went to Certaldo, San Gimignano, Siena, and back to Florence. The GPS in the car took us on the back roads through the gorgeous Tuscan countryside. We did take the autostrade from Sienna back to Florence to save time. It was the perfect amount of sightseeing for a one day car trip, with ample time to spend in each. In my opinion, Lucca is too far west to combine with a trip to San Gimignano and Siena.

acraven, thanks for the suggestion on Volterra.
I have been interested in the Etruscans and had visited Rome's Museo Etrusco in spring 16.

This "one-day bus tours" was offered in Florence ?

i don't think you need 5 days for Florence, beautiful though it is.

I will disagree with that depending on your interests? If you are into Renaissance art and architecture plus enjoy taking it in at a leisurely pace, then 5/4.5 days won't be too much. We had nearly 5 days, found PLENTY to fill our time, and had to put some things on the back burner for next trip.

The typical independent traveler devotes two full days to Florence (3 nights), dawn to night.
I don’t count organized tours. Those rarely spend more than a day in Florence (one or two nights), because they try to cover 15 European countries in 10 days. That’s no travel in my book.

So, if you are the typical independent traveler, if you stay 6 nights, you could take up to 3 day trips.
Siena is of course a must. If you start early, you could possibly swing by San Gimignano on the way back to Florence, just for a short visit.
Arezzo and possibly nearby Cortona could be another trip.
Lucca and possibly nearby Pisa is another.
Pistoia is also a possibility and very close to Florence.
Fiesole, up the hill from Florence, could be a nice afternoon and evening dinner.
The Chianti hills are very popular with wine lovers. However, for that you probably need a car or an organized wine tour (of which there are many).
Volterra and Monteriggioni are also popular destinations, but without a car or an organized tour, reaching them by public transportation is more convoluted.

Montepulciano, Pienza, and the Val D’Orcia in general, are too far from Florence for a day trip, IMO.

Agree with Kathy. You can definitely get five days out of Florence.