Why six million skeletons are stuffed into the tunnels underneath Paris

Ahh Paris, the city of lights, amour, beg bugs... but also a deep, dark past that lies underneath the famed city.

Beneath the city's chic streets, there are miles of tunnels — known as the Catacombs — that hold the bones of more than six million people.

The Catacombs snake 20 metres (65 feet) beneath the streets and are thought to cover nearly 2,000 acres (three miles), although less than a mile is accessible to tourists.

But how exactly did this sprawling labyrinth of skeletons come to be?

Frédéric Soltan/Corbis via Getty Images

The history of the Paris Catacombs starts in the late eighteenth century.

Like many other booming cities during the early industrial age, Paris was overwhelmed by death and disease. This resulted in overcrowded graveyards and cemeteries.

Les Innocents, one of the biggest graveyards in the city, reportedly reeked of rotting bodies, its smell so bad that local perfumers struggled to sell their goods.

That's when you know it's bad.

By May 1780, the cemetery was so overstuffed with bodies that the cellar wall of a bordering property split open under the pressure and caused a mass of half-decomposed bodies and disease to flood into the basement.

Can you imagine the site? And the smell.

Within months, authorities ordered the closure of Les Innocents and the city's other cemeteries and set out to transfer their contents to an underground site.

Frédéric Soltan/Corbis via Getty Images

The abandoned Tombe-Issoire quarries extended under Paris over approximately 2,000 acres and provided the perfect spot to store the city's dead.

Primarily between 1787 and 1814, graves were emptied of their bones and dumped into the mines, where quarry worked would then distribute and pile them into the galleries.

The Catacombs are home to a number of famous bones, including dozens of figures from French history and celebrated artists, such as Charles Perrault, who is known for writing fairytales like Little Red Riding Hood, Cinderella, and Sleeping Beauty.

Today, tourists can visit around 1.5 kilometres (0.9 miles) of the ossuary, although thrill-seekers have been known to delve deeper into the labyrinth through secret entrances.

Recently, TikToker Amanda Rollins warned people against venturing beyond the official museum, sharing the chilling reason you should stay away.

"There's people that live in there full time, there is a community of people that live in the catacombs," Amanda explained, recounting her own experiences living in Paris and what her ex-boyfriend had told her.

"They don't want tourists going in there, whether it's tourists like Americans, tourists like French people, they don't want people going in there, period.

"What they will do is when they see you coming in with your map and your flashlights they'll run up to you, grab your flashlight and grab your map and then run away."

There have been multiple cases of people becoming lost in the Catacombs, though they tend find an exit and return to the surface world eventually.

Even so, that's really creepy!