At the end of the 18th century, Paris was faced with a problem. Overcrowding in cemeteries inside the city itself had gotten so bad that they were beginning to collapse. Faced with bodies literally spilling out onto the streets, the decision was made to dig up the cemeteries and move the bodies underground to an existing system of mines beneath the city (these tunnels had been in existence for centuries, and had been used to quarry much of the stone used to build the city of Paris). By the end of the project, roughly 6 million bodies were moved down into these tunnels.

In the early 19th century, these bones were arranged in macabre, artistic patterns and the catacombs were opened to visitors.

Back in May, my wife and I took a trip to Paris, and visiting the catacombs was one of our top priorities. A word of advice for fellow travelers: we waited in line for three hours before reaching the entrance. The museum in charge of the catacombs only allows a few guests in at a time. While this makes the wait a bit daunting, it keeps the tunnels from getting too crowded with sightseers (which not only allows you to look at things more closely, it keeps the tunnels from getting too cramped and claustrophobia-inducing).

Reminiscent of Dante’s infamous Abandon All Hope, Ye Who Enter Here, the underground doorway sports an ominous placard engraved in French: “Arrête! C’est ici l’empire de la Mort.” Stop! This is the empire of the dead.

The doorway from the ossuary to the passage leading back to the outside world bears a similarly ominous plaque, this time in Latin: “Non metuit mortem qui scit contemnere vitam.” He does not fear death who despises life. These inscriptions, and the vast displays of bones, paint a complex picture of the articects themselves, long since reduced to the very bones they painstakingly arranged into a masterpiece.

To better fit the artists conception of what skeletal art should look like, the walls of the catacombs are built of mainly skulls and femurs. The other bones are there, but hidden: piled haphazardly behind the main display. The tunnels are damp, and some of the bones are covered in a thin film of green moss.

Even though the portion of the catacombs open to the public is long and almost overwhelming (not so much in the distance that you have to walk as in the sheer number of skulls lining every tunnel), it’s only a small portion of the overall complex. Dozens of other passages open in either wall and disappear into the darkness, but they remain securely gated off from visitors, keeping everyone on the one path that leads back to the outside world. There are no tour guides (audio guides are available, and helpful), but there’s nowhere to go except for path through to the exit. Which is good, because getting lost among piles and piles of bones sounds fairly disconcerting.

Although it wasn’t part of the tour, back in 2004 Parisian authorities actually uncovered a small bar and surveilance system set up in a remote part of the catacombs. While this sort of thing doesn’t seem to be common (as far as I’ve been able to tell), the system of tunnels is vast enough that it’s easy to see how they managed to pull that off (at least for a while).