Chapelle Saint-Sébastien is adorned with naïve wall frescos dating back to 1491, by Jean Baleison and Jean Canavesio.
Composed of two bays with exposed ribbed vaults, it was decorated around 1485-90 with frescoes by two famous Piedmontese masters: Giovanni Baleison and Giovanni Canavesio.
The careful construction of cut stone reveals a characteristic late medieval style. On the façade, we recognize a Virgin of Mercy between two angels, protecting the people with her cloak. Above, in the triangular gable, a Christ of Passion rises from the tomb. The background depicts a fortified city.