“The Mouth of Hell”
According to Graham Robb in Parisians, An Adventure History of Paris (2010), the origin of the street’s name is obscure, although some etymologists contend that it is simply a corruption of its original Roman name Via Inferior, in contrast with the Via Superior, Rue Saint-Jacques. Whatever the origin, on that day one week before Christmas, the gaping maw became known as the “Mouth of Hell”.
One of Louis XIV’s architects, Antoine Dupont, oversaw the reconstruction of the collapse. The trench had a depth of 26 metres (84 feet) and appeared to be an ancient quarry. Dupont had the underground walls consolidated and the street was reopened after only a short period of time.
Two years later, the king created the Inspectorate General Service of Quarries with the directive to inventory the empty spaces beneath the city and ensure that the collapse would not happen again. Guillaumot was appointed the first Inspector of Quarries and was supposed to assume his duties on April 4, but his start date got pushed back to April 24 due to bureaucratic delays.
Guillaumot was only supposed to inspect the site of the collapse and the work done by Dupont, but as he was driving to the Rue d’Enfer, he encountered a roadblock. He alighted from his carriage, brandished his credentials to push through the crowd, and saw the cause of the road closure—a new hole with a diameter of twenty feet that had appeared on Rue d’Enfer, half a mile closer to the centre of Paris.
The Collapsing City
As Guillaumot was to discover later, after deploying hundreds of cartographers and miners and inspecting the cavities beneath the Parisian streets, Paris was on the verge of literal collapse.
The city began as a fortified settlement on the Île de la Cité and on the banks of the Seine built by a Celtic tribe called the Parisii. The tribe was conquered by the Romans in 52 BC, and the Romans built an entirely new city called “Lutetia Parisiorum” (“Lutèce of the Parisii”), with its probable origin the Latin word “luta”, or “mud”, referring to the marsh along the banks of the Seine.
The Roman Empire is now known for its massive edifices that have withstood the test of centuries. The Romans undertook large-scale construction projects across its territories, using limestone and marble extracted from underground quarries. In building Lutetia Parisiorum, they dug building materials from quarries near the Seine. What once were below-ground were brought above-ground: the stones that built Notre-Dame and the Palais-Royal, for example, came from beneath Rue d’Enfer.
As the Paris population grew in size, more and more buildings were built on top of the quarries with shaky foundations that couldn’t possibly support the massive weight of an expanding city. The museums, palaces, churches, and mansions of Paris were standing on hollow ground. The Roman Empire collapsed, the French monarchy grew in power, history marched on—but no one thought to inspect the ground beneath Paris until Guillaumot came along.
The Catacombs
Guillaumot worked tirelessly, walking with miners below the ground to match the tunnels to the streets above, even devising his own numbering system to impose order on the quarries.
On May 31, 1780, another architectural catastrophe complicated Guillaumot’s plans: a wall adjoining the Cimetière des Saints-Innocents (Holy Innocents’ Cemetery) collapsed under the weight of the mass grave, and residents of the Rue de Lingerie suddenly found corpses in their cellars.
The cemetery was the largest cemetery in Paris and had been in use since the Middle Ages. It was the burial ground of dead Parisians for the past nine centuries: murdered Huguenots from the Saint Bartholomew’s Day Massacre, the victims of the Black Plague, people who had died even before Paris was Christianised.
Guillaumot recommended that the bones and bodies be exhumed and transported to an ossuary in the consolidated quarries. Later, it would be decided that the ossuary be the resting place not only of the dead from Holy Innocents’, but all of the dead buried in Paris. Emptying the city’s cemeteries began in 1786.
The Romans constructed underground cemeteries in Rome and called them catacombae. The word is of obscure origin and must have been derived from the Latin cata tumbas, “at the grave”. The new underground necropolis had an entrance in the Rue d’Enfer and, perhaps thinking of Paris’s previous inhabitants, Guillaumot christened it the Catacombs. At the bottom of a shaft in Montrouge, skulls, tibias, and femurs were arranged in columns, a subterranean wall of bones that visitors can still see today.
Above-ground, the Holy Innocents’ Cemetery was transformed to an herb and vegetable market. Place Joachim-du-Bellay now covers the site of the cemetery, with the “Fountain of Innocents” marking the centre of the square.
The revolutionary movement that would eventually topple the French monarchy reached its first climax in 1789. In 1792, Guillaumot, who was appointed by the king and therefore connected to the former regime, was thrown into prison for two years. He went right back to work as Inspector of Quarries upon his release in 1794, assuming as well the duties of head of the tapestry factory Manufacture des Gobelins. He continued mapping Paris’s underground tunnels until his death in 1807.
He was buried in the Cimetière Sainte-Catherine, but when the cemetery was emptied in 1883, the great architect joined the other dead Parisians beneath the city, in the Catacombs he had helped build.
Esplanade Charles-Axel Guillaumot
The portion of Rue d’Enfer that collapsed in 1777 is now part of the Boulevard Saint-Michel, with the remainder of the street named after Colonel Denfert-Rochereau, a French serviceman who defended Belfort during the Franco-Prussian War.
Guillaumot’s gravestone disappeared when Cimitière Sainte-Catherine was excavated, and no one knows exactly where his bones lie in the Catacombs. For more than two centuries, there were no monuments dedicated to the architect who had bestowed order upon Paris’s underground quarries.
This changed in 2017, when the Esplanade Charles-Axel Guillaumot was unveiled. The street named after Guillaumot is located in the 14th arrondissement near the busy Denfert-Rochereau train station, the entrance to the Catacombs, and the historic headquarters of the inspectorate he once headed—a fitting memorial to Paris’s hard-working and illustrious citizen.