The Palazzo Comunale, the Collegiata and Church of Sant' Agostino contain frescos, including cycles dating from the 14th and 15th centuries.

Chroniclers Lupi, Coppi and Pecori relate that during the Catiline conspiracy against the Roman Republic in the 1st century, two patrician brothers, Muzio and Silvio, fled Rome for Valdelsa and built two castles, Mucchio and Silvia (now San Gimignano).

The name of Silvia was changed to San Gimignano in 450 AD after Bishop Geminianus, the Saint of Modena, intervened to spare the castle from destruction by the followers of Attila the Hun.

[9] In the Middle Ages and the Renaissance era, it was a stopping point for Catholic pilgrims on their way to Rome and the Vatican, as it sits on the medieval Via Francigena.

[8] The city's development was also improved by the trade of agricultural products from the fertile neighbouring hills, in particular saffron, used in both cooking and dyeing cloth and Vernaccia wine, said to inspire popes and poets.

[6][9] In 1199, the city made itself independent of the bishops of Volterra and established a podestà, and set about enriching the commune with churches and public buildings.

However, the peace of the town was disturbed for the next two centuries by conflict between the Guelphs and the Ghibellines, and family rivalries within San Gimignano.

The rivalry was finally restrained when the local council ordained that no tower was to be taller than that adjacent to the Palazzo Comunale.

[9] There was little subsequent development, and San Gimignano remained preserved in its medieval state until the 19th century, when its status as a touristic and artistic resort began to be recognised.

It is triangular in shape and is surrounded by medieval houses of different dates, among them some fine examples of Romanesque and Gothic palazzos.

There are many churches in the town: the two main ones are the Collegiata, formerly a cathedral, and Sant'Agostino, housing many artworks from early Italian renaissance artists.

The Communal Palace, once seat of the podestà, is currently home of the town gallery, with works by Pinturicchio, Benozzo Gozzoli, Filippino Lippi, Domenico di Michelino, Pier Francesco Fiorentino and others.

Tea with Mussolini, a 1999 drama about the plight of English and American expatriate women in Italy during World War II, was filmed in part in San Gimignano.

The frescoes that the women save from being destroyed during the German Army's withdrawal are inside the Duomo, the town's main church.

The account of this episode is, to a large extent, fictional, because, although there are reports of intended retribution against the town,[18] there is no evidence of a plan to destroy the churches.