The Sedlec Ossuary is a small Roman Catholic chapel in the Czech Republic. It contains the skeletons of between 40,000 and 70,000 people whose bones decorate the chapel.
In 1278 an abbot named Henry traveled to the Holy Land and brought a jar of dirt back with him. He sprinkled the dirt over cemetery in Sedlec. When people heard of this pious act they started bringing their dead relative to be buried in the holy dirt. During the Black Death the site became a mass grave with many thousands of bodies. In the 1400s a Gothic church was built on the site of the mass grave and an ossuary was set up for the unearthed bones. It was in 1870 when Frantisek Rint was employed to decorate the chapel with the bones.