She’s known as the Mona Lisa of death masks.

In the 1880s, the body of an unknown young woman was found floating in the Paris waterway. Her face was cast into a plaster mold, preserving her shy smile for posterity. This was a traditional practice of those days, but the peaceful look on her resting features so captivated the French public that her death mask was mass-produced and soon hung in well-furnished parlors across the country.

And now one adorns a corner wall in Brooklyn. At the new Morbid Anatomy Museum and Library, a mold of the young woman, dubbed L’Inconnue de la Seine (“The Unknown Woman of the Seine”), shares display space with spirit photography, elaborate wreaths made from human hair, and other paraphernalia of grief in its inaugural exhibit: The Art of Mourning.