April 2024: Every once in a while, I manage to gather a group of friends for an incredible adventure. Exploring the illegal network of Paris’s Catacombs was one of those unforgettable experiences. Few places are as steeped in mystery as the Paris Catacombs—a maze of limestone tunnels initially dug during Roman times for quarrying building stone. Many of Paris’s oldest structures, including Notre-Dame Cathedral, were built with rock from these ancient quarries. Later, in the 1700s and 1800s, as Paris faced severe space constraints, city planners began moving the overflowing, unsanitary cemeteries underground. These cemeteries were filled with victims of plagues, executions from the French Revolution, and general overpopulation. In total, around six million corpses were transferred unceremoniously into the Catacombs, freeing up surface space for the expanding city.
The Catacombs span hundreds of miles beneath Paris, some tunnels lying as deep as 100 feet underground, with much of the system still largely unexplored. Besides serving as a final resting place, the Catacombs have had various other clandestine uses over the years, including as a hideout for French partisans during World War II.
The Catacombs are split into two sections. One small area is officially open to tourists, maintained and kept safe, with entry and exit through a souvenir shop. The much larger section, however, is vast, unregulated, and dangerous, with risks of cave-ins and getting lost. Cell phone and GPS signals are nonexistent underground, making the threat of running out of flashlight power very real. Because of these hazards, authorities have made it illegal to enter this part of the Catacombs, even establishing a special unit of “Catacomb cops” tasked with arresting trespassers and sealing entry points. But a few entrances remain accessible, and I’d known for years that it was possible to enter and explore the off-limits sections.
Of course, exploring without a knowledgeable guide and a map would be foolhardy. I’d long wanted to do this but had never stayed in Paris long enough to find a guide. Most locals familiar with the Catacombs—a kind of secret society known as “cataphiles”—are secretive and unwilling to bring outsiders along. I was also wary of unreliable guides, as there are rumors of tourists being robbed or abandoned down there. However, after months of research, I found two Parisian urban explorers on social media who seemed knowledgeable about the Catacombs and were open to guiding me and my friends. After negotiating the terms, I felt confident about the trip.
The only catch was that the guides, who have regular weekday jobs, could only take us on a Sunday night—the same day I’d be arriving in Paris after an 11-hour international flight with my family and 8-month-old baby. The thought of going straight into the Catacombs after such a long trip was daunting, but I was determined. Unfortunately, my airline, French Bee, was almost three hours late. Thankfully, the guides were still willing to proceed, and we adjusted the plan: they would pick me up directly from the airport and take me to the Catacomb entrance, where my friends Dan, Frank, and Wes would be waiting.
With my bag packed with essentials—extra flashlights, battery packs, snacks, water, dry clothes, and waders for the deep water sections—I met the guides at the airport, and we set off. True to my promise to the guides, who are dedicated to preserving the Catacombs and avoiding online exposure of its secret rooms, I won’t disclose our entry point. I’ll only say we entered through an abandoned railway tunnel dating back to Napoleon. Inside the tunnel, there was a barely visible, narrow opening that we had to squeeze through, headfirst, one by one. Once inside, we found ourselves in a small, dank room that reeked of stale urine.
Abandoned railroad tunnel we entered and walked for 1/2 a mile before entering the catacombs
Entering the Illegal Catacombs
Once inside the Catacombs, we didn’t linger; it wasn’t a place to stand around in. We had miles to cover before reaching the ossuary where the bones were located, which would take hours of navigating cramped, humid tunnels with low ceilings and, at times, water up to our waists. We moved briskly, with one guide leading at the front and the other at the back to ensure no one got separated. Even with our small group of six, including the guides, it was easy to lose sight of one another, and the silence made it difficult to hear anyone a few feet away.
The Catacombs were as dark and disorienting as I’d imagined. Numerous side tunnels branched off in different directions—some leading up toward potential manhole exits, others dropping down into shadowy pits. Colorful graffiti lined the ancient limestone walls, giving the place an odd, almost medieval funhouse vibe. But as we descended deeper, the graffiti gradually disappeared, swallowed by darkness and silence.
The waterproof waders I had bought for the trip turned out to be useless; they leaked, and my boots quickly became waterlogged. Eventually, I decided to ditch the waders entirely, which made it easier to walk.
Tunnels with water. In the deeper tunnles up to our waist, I put my phone away and didn’t take video
Tunnels with water.
Low ceilings in the older tunnels were common and difficult for me at 6.1′ to navigate
Ladder leading up to a sealed manhole cover
Cat Hole
Different areas of the Catacombs are linked by small passages known as “cat holes,” narrow openings just big enough for a person to squeeze through. Cataphiles created these for easier access between sections, though the authorities constantly try to seal them off. It’s an ongoing game of cat and mouse; as soon as the police close a cat hole, the cataphiles typically reopen it, maintaining their secret routes through the underground maze.
Secret entrance
Chambers
Occasionally, we came across small chambers where we’d stop to rest and have a snack. Some of these rooms featured intriguing sculptures—gargoyle-like creatures crafted by cataphiles—while another contained a set of coffins that seemed more symbolic than actual graves. It’s safe to say that cataphiles have a dark sense of humor. The Catacombs are filled with countless rooms, though we only had time to explore a few. One that I missed, but would love to visit someday, is a World War II-era bunker once used by the Nazis to combat French partisans hiding in the tunnels. Unfortunately, it was too far from our route to reach on this trip.
One of the rooms with makeshift graves created by the cataphilles for unknown reasons
The Ossuary
The main attraction in the Catacombs is the ossuary, the vast burial area where countless human remains were relocated. There are several ossuaries throughout the Catacombs, but the largest, holding the majority of bones, lies beneath Montmartre Cemetery—an ancient burial ground dating back to the 14th century. In the 1700s and 1800s, many bodies were transferred from this cemetery to the Catacombs due to overcrowding.
To reach this centuries-old section, we walked for hours, and then, suddenly, scattered bones began to appear on the ground. This area was my favorite part of the journey. We descended multiple sets of stairs, and side tunnels opened into hidden rooms stacked with layers of bones and skulls, some piled dozens of feet deep. Though I’d thought it might feel eerie to be among so many of the dead, I was surprised by the sense of peace instead. Rather than fear, I felt a quiet connection to these people who had once walked the earth. I was captivated, wondering about the lives they’d lived and the stories they might tell if they were alive today.
Dan climbing through a tunnel stacked with bones and skulls to get to the wall of skeletons
Tunnel of bones
Me in a tunnel of bones
Bones and more bones
Wall of bones
Wall of bones
A skull
Another corridor with bones and skulls
We encountered two bone thrones, creations of cataphiles over time. One was particularly intricate, and despite the potential disrespect to the deceased, we succumbed to our vanity and took turns capturing the quintessential photo on the throne, each posing as the dark overlord of the netherworld.
Me in the bone throne
Me in the 2nd more elaborate bone throne
We spent a total of six hours in the Catacombs and, remarkably, didn’t encounter a single other person. At one point, we heard techno music echoing faintly through the tunnels and even caught the smell of a cigarette, but we never saw anyone. On our way out, we attempted to exit through a manhole, only to find the lid sealed shut. In the end, we had to retrace our steps and exit through the same abandoned railroad tunnel we’d used to enter.
We emerged onto the empty, nighttime streets of Paris, covered in mud and the dust of human remains. My new cataphile friends kindly dropped me off at my hotel, where I slipped inside and, as quietly as possible, washed off centuries of Parisian history in the shower. I left my soiled belongings in the doorway to deal with the next day, then collapsed into bed beside my wife and daughter, ready for some much-needed sleep.