Le bois des fous was created in Folgoët in North Finistère. The name of this village comes from the nickname given to Salaün Ar Fol, "the madman of the wood" who lived in the wood where the village is now located. Salaüm is at the origin of a legend which led to the construction of the Notre-Dame du Folgoët basilica.  Shortly after his death in 1358, at the age of 48, a lily was discovered, taking root in his mouth and on which was written in gold letters "Ave Maria".

For centuries, a pardon has been held every year at the basilica on the first Sunday in September. The surrounding parishes, with their crosses and banners carried by more than 20,000 faithful in costume, set up the great procession in which two statues of the Virgin Mary (including the black kersanton Virgin) are carried under the outer loggia of the basilica. This 22-minute documentary film shows and leads this Breton procession in its own telluric and celestial dualities, at the crossroads of the religious, the legendary, the Celtic, the mystical, the magical, the historical, the authentic, the remembered and the secret, from which emanates withdrawal and entrenchment. R.Y