The Charrière site is a Franciscan convent. It is a unique place in the region. It consists of a Romanesque church which depended on Cluny from the 10th to the 12th century. Activities are scheduled during the summer. Find the full program here: prieuredecharriere.fr/12558_Programme-des-Estivales-du-Prieure-de-Charriere.html
Discovered a little by chance, I did not expect to miss it. These are the remains of a 15th century Franciscan convent, a little outside the village of Châteauneuf-de-Galaure in the Drôme des Collines.