In 1830, saintly Catherine Labouré was said to have seen a vision of the Virgin, who told her to cast a medal that copied her appearance - standing on a globe with rays of light appearing from her outstretched hands. This kitsch chapel - murals, mosaics, statues and the embalmed bodies of Catherine and her mother superior - attracts two million pilgrims every year. Reliefs in the courtyard tell the nun's story.