A little morbid tonight.

After the time of the Romans Paris began burying it's dead in municipal cemeteries. This went on for almost a thousand years. As Paris grew, it absorbed the cemeteries that had been outside its boundaries. In the Les Halles area of Paris a cemetery called Saints Innocents was a particular problem. The practice was to bury hundreds of bodies in large pits without coffins. When the hole was filled another was opened nearby. Eventually the hole would be reopened and the bones now devoid of flesh would be stacked in special buildings and new bodies buried in their places. This only worked for about about 500 years, and enormous numbers of citizens of the area became ill as a result of ground water pollution.
In 1768 the cemeteries had become such a problem that it was decided to move all of the bones and bodies to ancient Roman limestone mines outside of Paris. For years, every night, black draped wagons hauled the bones of the dead from every cemetery in Paris to a location outside the city where they could be distributed in the massive tunnel systems. Over SIX MILLION bodies were moved out of every location within the city limits. Some of the bodies had even been walled up in unused houses throughout the city.Today the "catacombs of Paris can be toured and the bones are artistically arrayed along with the monuments from the old graveyards. A sign over the entrance to the ossuary reads Stop! This is the Empire of Death!