The name derives from the name of the patron saint, Saint Oyen, to whom the parish church is entitled. A town located almost at 1400 meters of altitude in the Valle del Gran San Bernardo, along both banks of the stream Artanavaz, on the border with Switzerland. The location offers a perfect combination of good food, peace and sport with the nearby equipped ski resort of Flassin , with its 5 kilometers of trails, and the Foyer de ski de fond, a well-equipped, a modern sports centre.
In 1137 the Count of Savoy Amadeus III donated the lands of Chateau Verdun, located in the territory of Saint Oyen, to the fief of the Great St. Bernard. The Chateau was a kind of pertinence of the Hospital of Great St. Bernard and it became a hospice for travelers. The fief expanded enormously during the XIII century, causing to numerous disputes with the neighboring communities. Of particular complexity was the controversy over the possession of Alpeggio Citrin, by the Lords of Etroubles, Bosses and Avis. The territory was under the direct jurisdiction of the Savoy until the end of the XVI century. The latter, in 1584, formed the barony of Gignod which included Saint Etienne, Saint Martin de Corleans, Etroubles, Saint Rhémy, part of Allein and Saint Oyen. This fief was assigned to François de la Crete, as a reward for his dedication and services received.

Not to miss:

The Parish church dedicated to Saint Oyen, abbot of the VI century. It was probably built in the XII century, when the parish was formed, but its existence is documented only since the 1820s, a period when it was completely rebuilt. Restored in the XX century, it features a Bell tower with a square base with two rows of mullioned windows, which are quite distant from each other and surmounted by a spire-shaped cone. Inside it preserves valuable liturgical furnishings, including a silver reliquary with crystals dating from the XVII century, donated by a Swiss artist.
The Chateau Verdun, erected between the X and the XI centuries, was donated by Amadeus III of Savoy to the Canons of the Great St. Bernard, who used it as a hospice for travelers and a masterfully organized farm. It is a central architectural complex whose structure covers a square shaped base with four impressive looking roofed areas. Renovated in 1992, it still houses the Canons and is also a quiet place for those devote to education or reflection. The interior features fine furnishings and brilliant architectural solutions.
The old sawmill in the town of Prenoud.
The Park des Chevreuils, a well equipped fenced environment for the chamois and deers, with chalets for the housing of animals and their feeding. The park covers an area of 8000 square meters.
The Herbarium, built by the Canons of the Great St. Bernard, between 1850 and 1900, with 500 species of herbs and a specialized Library.