The Secret Tunnels Under Paris That Go Way Beyond the Catacombs

Most people who visit Paris know there are catacombs. You queue at the entrance on the Place Denfert-Rochereau, descend about 65 feet underground, walk through roughly a mile of tunnels neatly lined with the bones of six million Parisians, and come back up feeling appropriately unsettled. It is a genuinely memorable experience. It is also, in terms of what actually exists beneath the city, barely a beginning.

The tourist catacombs represent maybe one percent of the underground network. Below Paris runs approximately 180 miles of abandoned limestone quarries, interconnected tunnels, subterranean rivers, ancient cisterns, and forgotten infrastructure. Most of it is illegal to enter. A dedicated subculture of urban explorers, called cataphiles, spends considerable time exploring it anyway. The cata-flics, a small dedicated police unit, spends considerable time trying to catch them. Both parties have been at this for about 50 years.

How the Tunnels Got There

Paris is built on limestone. From the 12th century onward, as the city’s builders constructed Notre-Dame and the Louvre and the city walls, they needed stone, and the stone was directly underfoot. Quarrymen worked on all fours in underground galleries south of the Seine, cutting blocks with hammer and chisel, rolling slabs to shafts where men in hamster wheels winched them to the surface. This went on for centuries. Nobody really tracked it.

By the 18th century, Paris had expanded over most of its own foundation. In 1774, a street called Rue d’Enfer, which translates as Hell Street, collapsed. King Louis XVI sent his architect Charles-Axel Guillaumot to assess the damage. Guillaumot reported back that much of Paris could collapse. The city was sitting over a labyrinth of fragile quarries stretching for miles in every direction.

Louis XVI established the Inspection Générale des Carrières in 1777 to map and stabilize the tunnels. Over the following century, Guillaumot’s team worked systematically through the network, lifting ceilings, squaring angles, and consolidating walls. They also labeled everything: inscriptions on the walls included the inspector’s initial, the year, the sequence number, and the name of the street above. Some of those inscriptions are still readable. The old French marking “au couchant” means the western side of the street, where the sun would go to bed.

The Bones Came Later

The tunnels predate the bones by several centuries. The decision to put bodies into the quarries came in 1786, driven by a separate crisis. Paris’s cemeteries, including the massive Les Innocents which had served as a major burial ground since the 10th century, were overflowing. A retaining wall had collapsed next to Les Innocents, flooding a neighboring cellar with decomposing remains. The water table across the left bank was contaminated.

The solution was to move the dead underground. Workers transferred bones from overflowing cemeteries into the quarry system at night, partly to avoid shocking the public. They deposited bones of approximately six million people over the following decades. The entrance to the necropolis is marked with the words: “Arrête! C’est ici l’empire de la mort” — “Halt! This is the empire of death.”

Victor Hugo, who wandered the tunnels while writing Les Misérables, called them the city’s intestines. The section open to tourists today represents the organized, museum-quality portion. Behind the neat stacks of skulls and femurs lie the broader quarries, which are not orderly, are not illuminated, and are not open to the public.

What the Cataphiles Found

The modern cataphile scene began seriously in the 1970s, when Parisian rebelliousness got a fresh jolt from punk culture. Young people discovered they could enter the tunnels through forgotten doorways in their school basements, via unsecured manholes, through maintenance passages that nobody was watching. Once down there, they found approximately 180 miles of underground Paris that nobody was using.

They moved in. Parties happened. The old quarries hosted nocturnal discotheques, illicit art shows, and secret cinemas. Murals appeared on the walls, some requiring hundreds of hours of work and weeks of carrying supplies underground. Cataphiles built a bar in one chamber. A swimming hole appeared in another. Someone constructed a cinema with a screen and projection equipment and film references plastered across the walls. Someone else carved a wave in the style of the Japanese printmaker Hokusai across an entire sandy chamber, which other cataphiles have been repainting ever since. An art community built, self-policed, and maintained its own underground culture with its own rules and aesthetics.

The Parisian authorities banned entry in 1955, before the modern scene existed. The decree dates back to 1955, but the underground police have an understanding with seasoned cataphiles. Their main targets are tourists, who by their lack of knowledge expose themselves to risk of injuries and degrade their surroundings. In practice, fewer than five officers patrol over 180 miles of tunnels. The enforcement is selective.

The Patron Saint of Getting Lost

Every subculture has its mythology, and the cataphiles have Philibert Aspairt. Philibert was a doorkeeper at the Val-de-Grâce hospital who entered the catacombs alone in November 1793, reportedly in search of a wine cellar. His lantern went out. He could not find the exit. His remains were discovered eleven years later, a few steps from an exit he never reached, with a bottle of alcohol in his hand. Cataphiles now revere him as the patron saint of the underground, the cautionary example of what happens when you go alone and your light fails. His grave sits in the catacombs near where he died.

The practical advice that circulates among cataphiles follows from Philibert. Never go alone. Carry multiple light sources. Know at least two exit points. Stay with people who know the network. The tunnels include chambers where the ceiling rises to 30 feet and passages where you crawl on your stomach. Some sections flood seasonally. Some walls are unstable. The city has been progressively filling dangerous sections with concrete since the mid-20th century, which closes off passages and infuriates cataphiles who treat the network as cultural heritage.