While the rich had proper burials in places far from their neighborhoods, the poor were often buried in shared ditches under unsanitary conditions.

The Cemetery of the Innocents got the most attention. In 1775, numerous complaints had already been made. A terrible smell hovered over The Halles neighborhood. Over the years, the ground of the cemetery had risen by 8 feet to cover the constant inflow of cadavers, the amalgamation of the remains of 22 parishes.

Francois Pontrain, the last digger, was said to have buried 90,000 bodies in 35 years in 5 to 6 meter ditches.

The authorities investigated and learned that it was impossible for the people to keep milk, and that the wine was spoiling. The riverside residents were suffering from many illnesses. The whole neighborhood was contaminated.

In 1780, the wall of an intermediary cave in the cemetery collapsed under the weight of the bones, and many people were severely asphyxiated.

In 1785, the State Council ordered that the Cemetery of the Innocents be destroyed and converted into a public market.

The underground calcareous rock quarries were quickly thought of, and more precisely, the area referred to as the "Tombe Issoire". In this area, a few knights of the Saint Jean de Latran order, as well as certain Templiers, had already been buried. The Christian aspect of the area is pleasing.

And so it was on April 7, 1786, that the future ossuary was consecrated by the Vicar General of the the Archbishop of Paris. The transfer of bones from the Cemetery of the Innocents began that very night. At nightfall, covered wagons for the poor, and funeral chariots and catafalques for the rich left from the cemetery for the ossuary site. This work lasted 15 months. The other remains were thrown into a service hole located at 8 bis avenue Rene Coty.

As this went well, it was decided to destroy all the parochial cemeteries; hence, large waves of disinterments occurred in 1808, 1809, 1811, 1842, 1844, 1846, 1859, and 1860.

The catacombs also seemed to be an ideal place to get rid of the "cumbersome" dead, such as those from the first massacers of the revolution.

The public visits began in 1814. It became illegal to visit the ossuary in 1830 because at that time, unlike the present situation, it wasn't completely isolated from the rest of the network of galeries, and many visitors, intentionally or unintentionally, got lost inside. In addition, there were unfortunately many acts of vandalism.
Napoleon III decided to reopen the area and it was never reclosed until the beginning of 1995, when the ventilation work began.