We will only have 1 day in San Gimignano. Any
suggestions as to what we should not miss?
If you are into art, the church of Sant'Agostino has beautiful frescos by Benozzo Gozzoli. Nobody else there, lovely music quietly playing in the background. The Rocca (fortress remains) are a climb that rewards with a gorgeous view. Gelato break: the stand on the main road to the gate is packed, the one a block away on the parallel street is deserted.
Just make sure that a mass is not underway when you try to enter. If you are there for mass and properly dressed, you can enter. If not, you won't be admitted. When we were there, we were on a tour and had about 90 minutes in the town. As a mass was underway in the church, we were not permitted to enter.