The chapel, located in a panoramic area close to the vineyards at the gates of the Ramats hamlet of Chiomonte, was built between the 14th and 15th centuries and enlarged between the 16th and 17th centuries.
The interior is decorated with scenes from the life of Saint Andrew the Apostle, made at the end of the fifteenth century by the so-called Master of Coignet and Ramats, linked to the workshop of the Pinerolesi Serra. The Master of Coignet and Ramats, linked to the workshop of the Pinerolesi Serra, was active, as well as in Ramats, at the Coignet chapel and at the parish Church of Rochemolles in Bardonecchia. The holy arch, once placed outside the chapel and now a point of division between the presbytery and the prayer hall, is decorated with a splendid Annunciation, assimilated by critics to the one present in the parish church of Rochemolles. The area of the presbytery is, instead, decorated with scenes from the life and martyrdom of Saint Andrew, divided into thirteen frames of intense drama. The grotesque faces of the executioners of the saint are noteworthy, while on a stylistic level the lively use of colors and the inclusion of elements of the fashion of the time in the clothing of the various characters depicted stand out. In these frescoes, critics have highlighted the links, as well as with other buildings in the upper Susa Valley already mentioned, also with the depiction of the Evangelists made inside the Church of the Cordeliers (Franciscans) of Briançon.