The name derives from the French word "Castiglione". Chatillon is one of the most populated municipalities in the region after Aosta, situated at the point where the Valtournenche opens to the Central Valley at about 550 meters, in a sunny valley, on both sides of Dora Baltea and Torrent Marmore. It extends from the foot of the hill to the river, overlooked by Mount Zerbion to the North, by Barbeston and Cima Nera to the South, in an advantageous position which has made it an important center since ancient times. Today it is an industrial town, dedicated also to tourism with modern facilities, equipped with sports facilities and its location in the proximity of Saint Vincent. The center is dominated by the castles of Baron Gamba and Ussel, and preserves intact villages built in the XVI and the XVII centuries and in some districts it is possible to admire old medieval towers and some rural households, such as La Tour, Nèran and Conoz.
After the discovery of a prehistoric remains in Nèran, on the hill of Saint Clair, and near the castle Ussel, evidence the presence of settlements in these areas since pre-Roman times. The area was later conquered by the Roman army that settled there, by subtracting the land from its inhabitants. In medieval times it was a fief of the noble family of Challant, a compulsory transit and toll, the most important after Aosta. At that time the town was surrounded by fortified walls with four main entrances. Around 1361 the family of Challant-Chatillon ended with no heirs and the fief became part of the jurisdiction of the Savoy. In 1366 Ibleto of Challant bought the castle and after his death, it was inherited by his sons John and Francis. The latter died and his portion was acquired by his daughter Catherine, even though at the time, the tradition wanted that women could not inherit fiefs and castles. Other branches of the family Challant of Fenis and Aymavilles, contrasted this heritage and in 1456 Giacomo Aymavilles Challant, obtained the investiture of the fief from the Savoy, and besieged the castle until Caterina surrendered to him. With the death, in 1802, of the last heir of the Challant Family, the fief passed to Passerin d'Entrèves

Not to miss:

The Castle of Ussel located just beyond the Dora and built by Ebalo of Challant between 1341 and 1345. Looking at its structure, it shows the evolution of the time compared to previous periods: the walls are thinner than usual, the holes are flanked by windows. It features a rectangular shaped building and the corners of the South side have been enriched by two cylindrical towers, previously linked by a passage and protected by a wall with battlements. At the corners of the North side, the towers are square and center the keep, the perimeter is decorated with a horizontal strip characterized by arches carved in stone and mullioned windows that feature decorative elements, each one different from the other, the front door dell'Archivolto, of which remain only a few fragments of carved stone. The building was donated by Passerin Entrèves to the regional administration, after a careful recent renovation, it is now seat of exhibitions.
The Castle Baron Gamba located in the West side of Chatillon, in Crete de Breil, was refurbished in the early XX century, and features a park of about 7,000 square feet.
The Castle of Passerin d'Entrèves is one of the oldest in the region, built in one of the highest locations of the town. It was the residence of Challant in the XV century and Catherine Challant had a fortified wall and ditch built to protect themselves from the siege of the troops of Giacomo of Challant. In 1717 gardens were added and the lounge was decorated with stucco. In 1755 the castle was badly damaged by an earthquake, rebuilt the construction lost the typical shape of medieval buildings to capture the features of a more elegant building. In the second half of the XVIII century it was again restored and embellished. In the XIX century became the property of Passerin d'Entrèves, who had the ancient medieval tower located on the west side demolished and built a housing for the servants and stables
The Roman bridge over the stream Marmore composed of a single arch and covered with slabs of white marble.
The Church of St. Peter, overlooking the village, was built on the ruins of a temple dedicated to Augustus, as evidenced by three Roman inscriptions of the I-II century AD located on the site. It certainly is a very old building, the first official document that testifies the existence of the church dates from the late XII century. The original building, very different from the current one, was repeatedly remodeled throughout the XVII and XIX centuries. In the early XX century, the building was partly demolished to make way for the new church. Of the original structure remain the old sanctuary and bell tower with two rows of mullioned windows onto which opens an old door surmounted by a carved stone lintel of 1607. It preserves insides a baptismal font of 1789, the high altar in polychrome marble donated to the church in 1791. From the courtyard it is possible to admire a superb view of the mountains that overlook Chatillon and Saint Vincent.
The Parish Museum that once was the chapel that housed the family of Entrèves during religious services in the Parish Church of St. Peter.
The Chapel of St. Anne in Bellecombe, built in 1679, features a façade painted with images of St. Anne, the Virgin and Saints Peter and Grato.
The Capuchin monastery, an old house converted into a convent in the XVII century at the behest of Paul Emmanuel Challant. Annexed to the house there was a chapel dedicated to St. Grato, rebuilt between 1635 and 1642 and then dedicated to St. Francis of Assisi. The building was used for different purposes: in 1800 as a warehouse, school, hospital, barracks, until 1895, when it was purchased by the bishop of Aosta and still houses the community of Capuchins.
The City Hall constructed around 1850, features an decorated porch and three floors.
The Chapel of Saint Clair, located on a hill, was dedicated to Notre Dame du Chaterland. It has ancient origins and was rebuilt in 1663 and dedicated to Saint Clair, and refurbished again in 1878.
The Chapel dedicated to Saints Anthony and Bartholomew, the official building date is uncertain, but certainly rebuilt in the XVIII century.
The Tower of Nèran, which is part of a set of buildings with a square plan, built in the XII century.
The Ru du pan perdu, an old pipeline built in the XIV century that climbing on the rock surfaces, led the water from the stream Marmore over the hills to Saint Vincent.