September 1874. Parish of Noyal-Muzillac, Morbihan. In the hollow of a valley, the Virgin appears to a young miller of 17, Jean-Marie Le Boterff. No one doubts the statements of the seer because everyone knows his great devotion to the Virgin Mary and his repugnance for lies. This is why, when each evening he goes to the place of the apparition, many of them accompany him to recite the rosary and sing hymns. One evening, a woman brings him a statue of the Virgin. Jean-Pierre then sets up a hut in which he places the object.

In 1876, when Jean-Pierre Le Boterff joined the brothers of Ploërmel, where he died in 1888, an oratory was built and then, on March 25, 1882, the feast of the Annunciation, the first stone of the chapel was laid : the Kério chapel.