The chapel of the Miraculous Medal is the busiest room on rue du Bac and the hardest to find. It sits at the back of a courtyard behind a plain doorway, between shopfronts and the side wall of a department store, with nothing on the street to announce it. The courtyard walls are covered in small marble tablets, most carrying a single word: merci, thank you. Inside, people come in, kneel, buy a medal at the counter and go back out to the street. Nothing is staged for visitors.
In 1830 a young nun of the Daughters of Charity, Catherine Labouré, said the Virgin had appeared to her here and had asked for a medal to be struck. The Archbishop of Paris agreed to it, and the first fifteen hundred were struck in June 1832. Close to two million people a year now come through this courtyard, which places the chapel among the ten most visited sites in the city. Catherine Labouré's body lies beneath an altar here, and the shrine of Louise de Marillac, who founded the order in the seventeenth century, stands in the choir.