Overlooking the central Via Aubert near the Regional Library, the church was built in 1682-83 by the Brotherhood of Mercy, who had the task of assisting the prisoners and to accompany the condemned to the gallows. The Brotherhood gave the material and Jean-Boniface Festaz, general treasurer of the Duchy of Aosta and founder of the Hospice of Charity, paid the expenses of the workforce.
The nineteenth-century facade decoration in trompe-l’œil imitates an architecture that includes a painting of the Finding of the True Cross by St. Helena, mother of Emperor Constantine.
The interior contains various antique furniture from 17th to 19th century. The sumptuous main altar in baroque Valsesian style is probably due to the generosity of the Saint Ours’ prior Charles-Hyacinthe Beltram, who in 1737 made major donations to the Brotherhood.