The haunted Catacombs of Paris, France, are a massive collection of bones moved from cemeteries in Paris to the tunnels of underground stone queries. The bones were moved from the late part of the 1700s to the mid 1800s. People believe that the way the bodies were placed in the tunnel is disrespectful and causes the spirits to haunt the living. After being in the presence of the bones, many people claimed to have heard voices and were too afraid to enter again.
you know about Haussmannization, the grand remodeling of Paris in the 1860s, you may or may not know that the Catacombs of Paris were reconstructed in order to support the sprawling housing developments and massive boulevards that would come to define the city. Underneath the beautiful fašade of Paris is a structural support system built of human bones. In order to strengthen his structure and alleviate the sanitation issues that were being caused by past improper burial, Haussmann had his team of workers dig up the remains of many of Paris' graveyards and use them as building materials for his project. And what, if anything, do we know about disturbing graves? Right, it pisses the dead off. Though only a small part of the catacombs are open to the public, there are many secret entrances and tourists and trespassers alike have attested to its haunting with stories and sightings of run-ins with ghosts of a bygone Paris. Expect to see apparitions ranging from the ancients to the revolutionaries and don't forget your flashlight if you go hunting. It's dark down there. Here is a nice history of the catacombs and a personal ghost hunting story.