The San Gimignano museum is located in the ancient monastery of Santa Chiara which was later transformed into a conservatory for young ladies of good family and, finally, into a middle school. The complex, defined through an articulated series of interventions ascribable to the 17th-19th centuries, was recovered between the 1980s and 1990s. There has been set up an exhibition center of great interest which includes the Archaeological Museum, the Spezieria di Santa Fina and the Gallery of Modern and Contemporary Art "Raffaele De Grada".

The Archaeological Museum of San Gimignano preserves important testimonies that trace the oldest San Gimignano history, from the archaic Etruscan period up to the 18th century. The exhibition is divided into two sections: one dedicated to Etruscan and Roman art with finds from settlements and necropolises found in the area (including Pugiano, Cellole, and La Ripa) dating back to the VII - I century AD; the other is reserved for artisanal production activities, such as glass and ceramics, attested in the city during the Middle Ages.

The Spezieria di Santa Fina, annexed in 1253 to the hospital of the same name founded in the mid-thirteenth century, offers a careful recovery of furnishings and furnishings of the ancient health institutions of the city. The set-up reproduces the original structure and aromas of the pharmacy, one of the oldest in Tuscany, with the subdivision into the "kitchen", where medicines were prepared, and in the "shop", in charge of selling the products, which were contained in ceramic and glass jars of the highest quality, referable to a period between the fifteenth and eighteenth centuries, and which still accompany visitors with their beneficial aromas.

It is named after Raffaele De Grada (1885 - 1957) a well-known Milanese painter who, after traveling all over Europe, chose San Gimignano as his chosen homeland, the Gallery of Modern and Contemporary Art housed in the same complex as the ancient monastery of Santa Chiara . The recent legacy of the Pacchiani Collection enriches the art gallery with Italian paintings between the 1930s and 1980s by famous artists (Casorati, Campigli, Carrà, De Chirico, Sironi, Soffici, Mafai, Morlotti, Adami among others). The gallery is also the most important exhibition space in the city of San Gimignano, where frequent temporary exhibitions are held dedicated to the art of the nineteenth, twentieth century and contemporary art.