The oratory is close to Momo, on the ancient route of the “Via Francigena” and its origin dates back to the XII century. Ancient findings that came to light recently, witness the place was sacred already in Celtic age. The reworkings performed over the centuries, especially during the Renaissance, bring us to the present structure. It has only one nave with a single apse, the façade is saddleback style and the porch is supported by two small pilasters. The interior is large and valuable; it is marked with four spans, one of them is elevated to constitute the presbyter. The frescoes that decorate the religious building are of great value too; in the year 1520, the interior was covered with a decorative program by the Sperindio brothers and Francesco Cagnola. The result was an iconographical Bible according to what San Gregorio Magno preached: “the image is the analphabets’ writing”. The pictorial cycle starts in the apse zone where the Trinity in the mandorla supported by angels is visible. The figures of the Apostles with the Deeds of Mercy at their base are below,. Scenes of the Christ’s life follow each other. The cycle is concluded with the Great Universal Judgement. Outside, on the south wall, we can enjoy the devotional frescoes dating back to late in the XV century on the south wall: San Grato, Saint Anthony the Abbot, San Giulio of Orta, Saint Christopher and the Mercy.