In 1926, the farmers of the Biondi family discovered an Etruscan chamber tomb in the area of ​​Rignano near Castelfalfi, containing three limestone cinerary urns with mutilated anthropomorphic lids. A coin found in the tomb, a bronze semis of Caius Maiano, allowed it to be dated back to 190 BC.

In the 1980s, a tuff cavity used as a cellar was discovered in the area of ​​the I Bianchi farm, originally an Etruscan chamber tomb of the Hellenistic period, with a corridor leading to a cave with a central square room and three semicircular rooms forming a cross.

The document of December 6, 1230 attests to the passage of the community of Castelfalfi under the jurisdiction of the Podestà of San Miniato for security reasons.

Preserved in the State Archives of Florence, it reports that the consuls of Castelfalfi declare their submission to the Podestà of San Miniato, agreeing to pay taxes and offer labor services for the maintenance of the territory.

Furthermore, the community had to donate a 10-pound candle to the church of Santa Maria di San Miniato every year on August 15. This document marks the loss of autonomy of Castelfalfi and its integration into the Florentine Dominion.

Born as a Lombard garrison, the first evidence of the Castelfalfi Castle dates back to the 14th century during the Florentine hegemony in the Pisan area.

The two original towers, dating back to the 14th century and belonging to the Guelph Party, were mainly used to defend the territory. In 1480, members of the Caetani family declared that they owned the castle, which at the time consisted of two towers placed to protect and control the valley.

During the 15th century, the Caetani family took control of Castelfalfi and it was Giovanfrancesco Caetani and Costanza de' Medici who, after their marriage in 1489, renovated the castle, transforming it into a noble residence, which they chose as their home.

Among the families who led the community in the following centuries after the Caetani were the Desideri, the Tornaquinci and finally the Biondi family.

The first evidence of the parish church of San Floriano in Castelfalfi dates back to the end of the 13th century. San Floriano, a Christian martyr from the 3rd century AD, is invoked as a protector against fires, droughts and other natural disasters, and is celebrated on May 4th.

Although remaining within the diocese of Volterra, in 1491 the parish church passed under the jurisdiction of the Chapter of the Cathedral of Santa Maria del Fiore.

The parish church has undergone important architectural modifications, one in the 16th century and another in the 20th century. In 1619, the lay company dedicated to the Virgin Mary was founded, whose headquarters are to be placed in the area, still visible and visitable today, located to the right of the central body of the church.

Antonio Biondi (1848-1929), a native and resident of Castelfalfi, was a patron of botany. He financed a historic expedition to the East to search for new plants, experimented with innovative cultivation techniques and was passionate about plant fossils.

His most famous undertaking was financing the Franciscan missionary Father Giuseppe Giraldi on an expedition to China between 1888 and 1901.

The strong bond between Biondi and Father Giraldi led to the discovery of the Lilium Biondi and the Magnolia Biondi, which forever linked Biondi and Castelfalfi to botany.

It is plausible to imagine that Biondi planted bulbs of his Lilium or seeds of his Magnolia in the Italian garden in front of the villa where Biondi lived; later, during the 21st century, a small residential building was built near the garden, today known as Casa Giardino.