We will have just one day to visit both Siena and San Gimignano. I do not know which one is best to see first logistically. I know there is a train that goes to Siena and we can get off at a particular stop and take a bus in to San Gimi. How does it work if we decide to get off the train to visit San Gimignano and get back on a train later to go to Siena if our tickets go from Florence to Siena?
Also, if we visit Siena first we will have the same off and on train situation. Do we need to buy separate tickets at the Firenze SMN station for Florence to whatever town we should see first, and another for the other city back to Florence? I am not sure if we can get off and on within a certain timeframe.
I have purchased all of our primary train transportation for our trip already. It's just that some of these day trips or legs of trips that can be issues, so I want to wait and buy those tickets when we are there.