The Cassero di Fulignano and its geometry. Architectural and structural restoration of the Colonica di Fulignano in the municipality of San Gimignano, Siena

The architectural complex known as the Colonica di Fulignano, located in the municipality of San Gimignano in the Province of Siena, includes a farmhouse and other buildings. During the survey required to develop the architectural and structural restoration project for the entire complex, the fortified structure of the cassero emerged. The first historical records document the existence of a fortified residence near Casaglie named curtis Fulignano and date back to the 10th century. The building was part of the feudal holdings of Marquis Ugo of the Lombard gens (994). The historical significance of the site is primarily linked to the intercommunal struggles that characterized the 12th and 13th centuries. The property, very close to the Via Romea or Francigena, thrived due to its proximity to San Gimignano and was involved in the events that saw complex political plots for territorial dominance between Florence on one side and Siena on the other. The story of the siege of Casaglia Castle in 1176 and the possibility that this building had been the residence of the imperial messenger, who sought mediation between the municipalities of Volterra and San Gimignano against their own bishop count, gives importance and knowledge to the site. The essay aims to present, above all, in addition to the historical research and the restoration project, the peculiarities that emerged during the survey phase. These peculiarities are very interesting for determining the construction exegesis of the complex, for finding the geometric proportions and for determining the fortified typology, in particular, recognizable in the cassero, where even today one can discern some architectural styles that trace the whole thing back to the piombante fortified architecture of the 12th century and in particular to the building typology between the cassero and the casa forte or casa torre.