It remains a strange, gloomy place but these columns, these walls of bones and skulls, erected have something special. For me, it's a must visit in Paris.

It's just bones. I would love to be able to explore the unofficial catacombs, but it is difficult to find a guide for this more "extreme" and above all prohibited trip because it remains dangerous.

The catacombs of Paris, term used to name the municipal ossuary, are originally part of the old underground quarries located in the 14th arrondissement of Paris, linked together by inspection galleries. They were transformed into a municipal ossuary at the end of the 18th century with the transfer of the remains of approximately six million individuals, evacuated from the various Parisian cemeteries until 1861 for reasons of public health. They then took the abusive name of "catacombs", by analogy with the underground necropolises of ancient Rome, although they never officially served as a place of burial.

Located 20m (65.62ft) below the surface, the part open to the public is approximately 1.7km (1.056mi) long. But this represents only a tiny part of the vast underground quarries of Paris, which extend under several arrondissements of the capital. There are also other underground ossuaries in Paris, inaccessible to the public, and which remain particularly unknown.

Among these bones, many celebrities from the history of France buried in Paris also join this final burial place. Thus, Nicolas Fouquet (superintendent of Louis XIV), the minister Colbert, Jean-Baptiste Lully, Charles Perrault, Racine, Blaise Pascal, Montesquieu, Danton, Robespierre; the executor of Marat Charlotte Corday, Lavoisier, and many others have joined these pillars and walls of anonymous people.

The catacombs do not only receive official visitors. In 1897, a clandestine concert was given there to around a hundred guests from around Paris. There are also unofficial catacombs, most of whose entrances are difficult to find. There are plates on the ground in Paris that we would take for simple sewer plates, but which allow access to service tunnels. Then, deeper, to the catacombs. There are a lot of different places. In particular, the Beach, where you can sit comfortably, some have even organized an evening for Halloween, with a DJ and disco balls. You can also discover other rooms, such as the Electro room, with super high ceilings or the bunker, built by the Germans during the war. All have a soul, works of art and facilities made by the cataphiles.