The structure and its surroundings were known as early as 1463 under the name of “The Lion’s Inn” where a curious innkeeper, nicknamed the Cacciavillani, entertained illustrious travelers. In 1666, the princely house of Chigi acquired the inn and engaged Carlo Fontana, a Bernini apprentice, to carry out its restoration. The building became the well-known postal relay of the Via Cassia, an ideal rest stop for pilgrims and merchants. Once it was inserted in the itinerary of the Grand Tour, it hosted the likes of Goethe, Alfieri, and Belli. In the 19th century it housed Napoleonic troops sent to the area to eradicate highwaymen from the nearby Baccano Valley. In the mid-nineteenth century, thanks to the intuition and passion of Otello Pulcini for this 16th century architectural jewel, serious restoration work was begun which, followed with loving dedication by the heirs of the Di Felice-Pulcini family, has now brought Il Postiglione back to the splendor of the Chigi.

Recent archeological excavations within burgh of the old Chigi Mail Stop have brought to light a well-preserved section of the original ancient Via Cassia. The well-known consular road represented the principal artery for traveling north from the capital of the empire. This road, in fact, was built by the Romans who, after conquering the lands of Vejo (396 B.C.), decided to reorganize the entire road system in the area. It is precisely in the segment which runs within the property where, according to the narration of Father Adone in a 5th - 6th Century text, Saint Alexander suffered his martyrdom.
The Romans set up a first post station in this valley in the 1st Century B.C., known as the Mansio, where travelers could find hospitality and the comfort offered by the nearby hot springs.

The oldest and still the most appreciable element of the entire structure is the Trough which, with its imposing presence, captures immediately the eye of the passer-by. The central position of this structure has remained unaltered through the centuries. In fact, the Trough, perfectly preserved from the erosion of time, brings back to mind the poetry of the drinking fountains and the public washing areas of old.

The small bell tower which overlooks the main entrance to the Old Post advises the guest of the presence of a chapel which the Princes Chigi decided to dedicate to the memory of the Bishop of Baccano. The saint, as one can read in the apocryphal text written by the priest Adone, was subjected, under the Emperor Caracalla, to a twofold torment. Initially condemned for having carried out the evangelization of this territory, he was first tried; then condemned to be burned at the stake. Seemingly untouched by the flames, he was beheaded in front of the 20th milestone marker of the Cassia, close to the Chigi trough. The valuable fresco dating from the 17th Century, which occupies the center of the chapel, reminds the visitor of this great example of Christianity.

In several places around the structure one can clearly distinguish the coat of arms of the noble Chigi family, wellknown merchants originating from Siena. To add to their coat of arms – six Siena mountaintops surmounted by a star, symbolizing the magnificence of the family name - Pope Julius II granted permission, at the beginning of the 16th Century, to include the oak, symbol of the Della Rovere family. Already from the Patio of the Old Post, first point of access for carriages and travelers, it is possible to view the noble family’s coat of arms. Today, an old carriage permits the visitor to appreciate the atmosphere of “travels on wood”, while the original fifteen hundreds main door allows access to the rooms which hosted illustrious guests.