Geobulletin alpha

News from the Geoblogosphere feed

New from Snet: Lithologs, a new tool to create lithological/sedimentological logs online..

Blog post recommendation

Geological Legacies of the Paris Basin: Part II – Subterranean Limestone Quarries and Catacombs of Paris

"...Paris has another Paris under herself…which has its streets, its intersections,
its squares, its dead ends, its arteries, and its circulation”
Les Miserables, Victor Hugo, 1862

For a discussion of the tectonic evolution of the Paris Basin, its Lutetian stratigraphy and the gypsum deposits of the Right Bank, please visit my previous post entitled Geological Legacies of the Paris Basin: Part I - Plaster of Paris, the Windmills of Montmartre, the Park of Buttes-Chaumont and a New Artistic Creativity here.

Stroll the narrow cobbled streets and broad boulevards on the Left Bank of the old French capital. Enjoy Paris’s beautiful storefronts, its exquisite monuments, museums, parks and stunning architecture. Languish in a sidewalk café or dine in a fashionably chic bistro. For the casual observer, it’s impossible to imagine what lies underfoot – 20 to 25 meters below street level.

Paris is a city of layers – both above ground and below. Its underground has many new additions, while others are vestiges of the past, often lost and forgotten. Some are accessible to the public, and others have been sealed for an eternity.

There are Roman Empire foundations and more recent wartime shelters, Medieval basements and mysterious church crypts, musty wine cellars and shadowy mushroom farms, and subterranean shopping malls and multi-level car parks. Factor in 1,305 miles of storm drains and sewers, 133 miles of Métro and RER railway tunnels, and countless miles of utility lines and pipes for water, gas, electricity and telephone. Standing on the streets of Paris, you'd never know what's under foot - unless you looked at a map of the underground that mirrors the landscape above.

Modified from the Atlas du Paris Souterrain – a highly-recommended source of information!
 Yet, there exists an even deeper layer! On the Right Bank, the buttes of Montmartre and Belleville are riddled with gypsum quarries. On the Left, Paris is honeycombed with a labyrinth of over 200 miles of cavernous limestone quarries replete with a macabre section known as the Catacombs – after the ones in Rome.  

The Catacombs is a dimly lit, musty maze of galleries and corridors lined with the bones of 6,000,000 (seven by some counts) disinterred Parisians. In one section, a water-filled well contains the stratigraphic contact of the Lutetian age 45 million years ago. How did these two “cities” evolve? How do they co-exist? A luminous City of Light above another of shadows and darkness.

The city of Paris occupies a tiny portion of the extensive Paris Basin – a 140,000 square kilometer shallow epicontinental trough of flat valleys and low plateaus in the north of France. On a larger scale, the depocenter of the Anglo-Paris Basin, that spans the English Channel into Great Britain, resides on the continental shelf of the Eurasian plate. Its foundation is a Late Proterozoic Cadomian-late Paleozoic Variscan crystalline basement. Please visit my post Part II for the Paris Basin’s juicy tectonic details here.

Paris (red dot) within the extensive Anglo-Paris Basin on a
Jurassic through Neogene Surficial Geology Map During the late Paleozoic, the basin began to form subsequent to extensive orogenic collisions that formed Pangaea in the western hemisphere. By the end of the Mesozoic, the basin (along with the assemblage of France, Belgium, Great Britain, Scandinavia and Western Europe) was tectonically transported to the eastern hemisphere on the Eurasian plate when Pangaea fragmented apart and the Atlantic Ocean opened its waters.

The basin’s strata were deposited in a multitude Tertiary age transgressions and regressions of tropical seas that flooded the epicontinent of Western Europe. Formed in a mixed environment of marine, coastal, lagoonal and freshwater conditions, deposition was followed by compaction, cementation and eventual lithification.

The sedimentary rocks that formed - during the Eocene epoch in particular - built the city of Paris: Bartonian age gypsums (gypse) for plaster of Paris on the Right Bank (north side of the river Seine) and Lutetian age limestones (calcaire grossier), chalks (craie) for lime-based cements and paints, clays (argile) for tiles and bricks, and sand (sable) for masonry on the Left Bank (south of the river). The deposits on each side of the river Seine are between two low plateaus, Montmartre and Montparnasse. Both banks were exploited from under the city, as Paris grew and expanded on the surface.

Fortuitously for Paris’s architectural future, the axis of the Tertiary age anticline of Meudon (red dotted line below) passes south of the city. The flexure allowed for the excavation of Paris’s geological bounty of gypsum from the Right Bank and deeper, coarse limestone from the Left.

Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013

The geologic transect (black above) extends across the basin from north to south and is represented cross-sectionally below. Note the availability of Lutetian limestone (calcaire grossier) south of the Seine on the Left Bank and gypsum (gypse) north of the Seine on the Right Bank in Montmartre. The vertical scale across the basin is greatly exaggerated, making Montmartre appear like the Matterhorn.

Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013

Thus, gypsum has been extracted in the hills of Paris on the Right Bank from Menilmontant, Montmartre and Buttes-Chaumont areas of the 18th, 19th and 20th arrondisements, respectively. Limestone was mined under the small Parisian hills of Montparnasse, Montsouris, Montrouge, the Butte aux Cailles and the Colline de Chaillot, largely on the Left Bank. 

Topographical Considerations of Paris
Modified from

The areas of Right Bank gypsum (green clusters) and largely Left Bank limestone (red) exploitation can be seen highlighted on this Paris map of 1908. The direction of flow of the River Seine is shown in black arrows.

By 53-52 BC, the Romans had conquered Gaul (roughly France and Belgium) and the Celtic Iron Age tribes living in the region. Within the Paris Basin, that included the Parisii, living on the banks of the river Seine. The Romans called their settlement on the hills south of the river Lutetia Parisiorum or Lutece in French. The name was derived from a Parisii word meaning marsh or swamp. In turn, geologists borrowed the name for the Lutetian age - a division of the Eocene epoch of the Cenozoic Era- the time in which the limestone called “Paris Stone” formed – 47.8 to 41.3 million years ago.  The decision to settle above the banks of the Seine was governed by its ideal location for trade, defense and availability of raw materials especially water and the limestone for Roman buildings, military fortifications and roads. The Roman and Medieval era that followed produced lasting design elements for the development of the city from the Renaissance through the 21st century.  Please take note of the Roman open quarries (right) in the vicinity of the River Bievre near its confluence with the Seine (lower right), and the Arenes de Lutece amphitheater.    A DOZEN CENTURIES OF LIMESTONE EXPLOITATION
The Romans in the 1st century and the early Parisians to the end of the 12th century acquired coarse limestone for structures in the most instinctive of ways – from above ground where it was most convenient. It was removed from open quarries (in French) where it had been exposed by erosion such as the region of the Seine’s ancestral tributary, the Bievre (see above). The technique was primitive, but the rock was readily available and had existing natural fractures that facilitated its extraction. One such quarry, virtually unrecognizable today, lies within the heart of Paris beneath the Arena of Lutece, a partially restored Roman amphitheater. Once considerably larger, the majority of the arena’s limestone has been repurposed into structures subsequently built throughout the millennium.   

By the end of the 12th century, medieval Paris had become a medium-size, walled city with a population of 25,000 surrounded by countryside of farms and vineyards. The extraction of surface limestone was replaced by underground workings to satisfy the sharply increased needs for building construction such as Notre-Dame Cathedral, the Louvre Palace and the ramparts of the city.
Mining below the surface also minimized the excavation of overburden, allowed deeper fine-grained deposits to be reached and conserved topsoil for farming immediately around the growing city. The first underground excavations were essentially extensions of the open quarries by digging horizontally into a hillside exposure (left diagram).  Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013  PILIERS TOURNES
The first mining method employed the “room and pillar” technique, called piliers tournes. After a horizontal tunnel was excavated, perpendicular and then parallel tunnels were added (right diagram). The result was a maze of interconnecting passageways with the weight of the ceiling supported by a grid of massive columns of untouched, solid limestone. It helped to prevent collapse of the undermined roof, but a significant portion of excavated material was lost.  In the 15th century, vertical wells were sunk and then tunnels were dug horizontally from there. In order to raise limestone blocks to the surface, wheeled wooden winches reminiscent of “squirrel” wheels were driven by workers climbing rungs, oxen or horses to raise blocks of limestone vertically. The system could haul up large slabs that weighed as far as 30 meters down.  Modified from M. Vire of MNHM and Jean-Pierre Gely, 2013  These mining techniques were also used on gypsum deposits for plaster of Paris in Montmartre and the Belleville hills on Paris’s Right Bank. Although artificially engineered, the grotto at the Park of the Buttes-Chaumont is reminiscent of the cathedral-like excavation structures that undermine the region.     HAGUES ET BOURRAGES AND PILIERS A BRAS
In the 16th century, the mining method of hagues et bourrages was employed that was economically productive and structurally sound. Instead of tunneling horizontally into the exploited table of limestone, miners would extract stone progressively outward from a central point. When the ceiling became sufficiently unsupported, a line of stacked piliers a bras was erected from the floor to the ceiling. When extraction continued outward, a second line of stone columns was added, which were then transformed into walls or hagues as the space in between was backfilled with waste rubble or bourrage.  

For a fantastic and imaginative 3-D tour of the evolution of Paris beginning with the early Celtic settlement, check out the video here.  A fine appreciation will be gained for the volume of limestone that was extracted beneath the Left Bank during the building of the city. SUBSIDENCE SINKHOLES ON MINED-LAND
The first underground limestone quarries were located in Paris's suburbs (faubourgs) on the Left Bank. As the city continued to grow, new underground quarries with interconnecting galleries were developed on the city’s expanding periphery. Old abandoned quarries fell into oblivion and were gradually built over.  Although the undermined state of the Left Bank was known to city architects in the early 17th century, Parisian’s became painfully aware of their precarious existence over the subterranean voids when they began to cave in. At first many thought it to be the work of the devil. Called subsidence sinkholes (fontis in French), the cave-ins varied in size with some affecting houses and others affecting entire streets.  Formation and Evolution of Subsidence
A fontis is a cavity that develops when the roof of a subterranean gallery caves in.
A cloche is the rounded top of the rubble pile.
Modified from Daniel Munier and from M. Vire The arched void forms that migrates upward as the ceiling rocks gradually tumble in. When the sinkhole finally breaks through the surface, the rounded top of the rubble pile or cloche can be viewed within the sinkhole from above - giving the cavity that has formed a bell shape. These sinkholes should not be confused with those that occur in a karstic landscape, which develops under a cover of soluble rocks - also limestone - via acidic water that has acquired atmospheric carbon dioxide.    CATASTROPHE IN THE MOUTH OF HELL
When the largest collapse occurred in 1774, a wave of panic spread through Paris. A giant sinkhole catastrophically swallowed a busy Parisian neighborhood including roads, buildings, houses, horses, carriages, oxcarts and throngs of people along Rue d’Enfer (now called Boulevard Saint Michel near Avenue Denfert-Rochereau). Appropriately, enfer is the French word for “hell,” and the gaping hole in the earth became known as the “mouth of hell.” The quarries that built the city of Paris were literally threatening to destroy it - neighborhood by neighborhood.
How ironic! The limestone that went into the construction of Notre-Dame, the Palais-Royal and the mansions of the Marais on the surface of Paris actually had come from the quarries beneath Rue d’Enfer – now taking revenge upon the city. “Paris (had) begun to devour its own foundations – sand for glass and smelting,
gypsum for plaster, limestone for walls, green clay for bricks and tiles.” From Graham Robb’s “Parisians: An Adventure History of Paris”
In response to the fear of collapse, King Louis XVI designated a commission to investigate the state of the Parisian underground on April 4, 1777. It was called the Inspection Unit for Quarries Below Paris and Surrounding Plains. The head of the newly minted office - appointed by the King by chance of fate only a few hours before the collapse - was an architect named Charles-Axel Guillaumot, who held the position of General Inspectorate of the Quarries (IGC) until his death in 1807 - in French, Inspection Générale des Carrières.   “Guillaumot inspected the "gaping wound as an explorer could contemplate the shores of a new continent.”
Author Graham Robb

This “Savior of Paris" that the city owes so much set about to inspect and map the fragile voids under the entire city, many of which were illegal and uncharted but most abandoned and forgotten. His goal was to excavate them where needed and reinforce (consolidate) them from future collapse. Virtually every chamber was mapped and assigned a name that corresponded to the street above. The inspected walls still bear his chiseled signature, a "G" and date.


 Following in the tradition of Guillaumot, engineers from the Inspection des Carrieres generally signed and dated their consolidation projects by carving their initials, order number and the years the work was carried out into the walls. Fleur-de-lis, the royal symbol of the French Empire, were obliterated from most of the signatures during the French Revolution. A DOUBLED PARIS
In order to safeguard public roads and of course the King’s properties, Guillaumot erected pillars from the quarry floors to their ceilings, “retrospectively-created foundations for the edifices built on the surface” (Gilles Thomas). The result was that every undercut surface street was doubled by a gallery that followed the same layout. In a sense, Paris became a mirrored city with one above ground and the other below. This allowed the evolution of subsidence voids to be monitored and shored up as needed. The same can be said of the modern city of Paris with its underground double. Here's an example from the 13th arrondissemont.  From In Guillaumot’s own words: “To monitor the preservation of these constructions at all times,
It was necessary to render them accessible; to this effect,
a gallery wide enough to allow passage of construction materials was left under
and within the public way; at the gallery’s farthest point, another wall was built.
Perpendicular galleries were dug here and there to enable communication between
both sides of the public way and to allow movement from one gallery to the next.”
(Memoirs on the Work Ordered in Quarries in Paris and Adjacent Plains, 1804) LES CIMETIÈRE DES SAINTS-INNOCENTS - THE SAINTS-INNOCENTS CEMETERY
Another peril was threatening the city – an insidious one that had become equally intolerable and every bit as dangerous. Paris’s cemeteries had become horrifically overcrowded. The earliest burial grounds were on the southern out-skirts of the Roman-era city on the Left Bank - outside the city! By the 4th century, burials had moved to the Right Bank on filled-in marshland - within the city. In particular was the property of the Saints Innocents church in 1130 - named after the biblical narrative of the "Massacre of the Innocents" by Herod the Great, the Roman-appointed King of the Jews.  No larger than a city block and literally within a few blocks of Notre-Dame in the midst of Paris’s densely inhabited area in the current district of Les Halles, problems began to pile up, literally. The foundation of Paris’s first Christian churches were somewhat removed from the center of population and many became crypts for those seeking a final resting place closer to god, a service only available to the wealthy. Common folk were buried outdoors on consecrated clergy property, close to their creator in the "fresh" air. One would think!  Saint-Innocents had become Paris’s principal cemetery, although there were countless burial grounds in the city. Saint-Innocents was adjacent to the city’s  principal marketplace Les Halles, where fresh farm products were sold daily. Burying the dead in town was a radical departure from the norm, contrary to logic, sound urban planning and public health. The red ellipse encompasses the Cemetery of Saint-Innocents that included the central burying ground, the church and the surrounded charnel house. Notice the proximity of Saint-Innocents to the central market Les Halles - now known as Forum des Halles. This ambitious, aerial urban map before the city’s redesign by Baron Georges Eugene Haussmann is but a small section of Paris with accurate detail of every building drawn down to the windows. You can visit the entire city map here. 
Turgot-Berez Map Plan of Paris
Modified from
By the end of the 19th century, the burial ground in Saints-Innocents has become a two and one half meter-high mound filled with over ten centuries of dead bodies largely from Paris’s 22 parishes – perhaps two million. The corpses had accumulated from natural causes, disease, famine, wars, and the collected remains from hospitals such as the Hôtel-Dieu and the morgue. Other Parisian parishes had their own burial grounds, but the conditions in Saints-Innocents were by far the worst.
LES CHARNIERS - THE CHARNEL HOUSEIn an attempt to relieve the overcrowding, Saints-Innocents was enlarged and surrounded by a high wall. What had begun as a cemetery of individual sepulchers (burial chambers such as crypts and tombs) had become a site for mass graves with large numbers of bodies buried in a single pit. When a mass grave was filled, a new one was initiated. And so on.

To make room for more burials in the 14th and 15th centuries, charniers or charnel houses (from a Latin derivative relating to flesh) were constructed around the burying ground to act as a repository for the overflow of corpses from the burying ground.


The long dead were exhumed and their bones were tightly packed into the walls and roofs of the charnier galleries. Bones were stacked in an almost artfully decorative pattern, while outside, rotting corpses on the grounds poisoned the air with a nauseating stench. Those living in proximity to the cemetery and certainly those downwind were the first to suffer. Broth and milk were said to sour within hours. The tapestries of merchants in nearby Les Halles discolored quickly. Wine turned to vinegar and resting one’s hand on damp, moldy walls was a risky endeavor. In nearby churches, the generous use of incense was insufficient to mask the foul stink. The French writer Louis-Sébastien Mercier (1740-1814) wrote:  “The stench of cadavers could be smelt in almost all churches; …the reek of purification continued to poison the faithful. Rats live among the human bones, disturbing and lifting them, seeming to animate the dead as they indicate to the present generation they among which they will soon stand... They (the bones) will soon all turn to chalky earth.”
A close up of the charnel house shows the skulls stacked in the upper tiers, while rotting corpses literally littered the burying grounds. Now lost but recorded in manuscripts, a mural of Danse Macabre or the Dance of Death was painted on the south wall within an alcove of the charnel house. Represented in many languages and countries, the theme dates from 1424-24. No matter one’s station in life, the universality of death depicted in the “dance” is an artistic genre of late-medieval allegory. It was meant to remind people of life’s fragility and the vainness of the glories of their earthly lives. A view of the burial grounds was likely all that was need!

 Wikipedia  Further insight into the unhealthy conditions at Saint-Innocents can be gleaned from Mercier’s description of the insalubrious state of affairs at the hospital Hôtel-Dieu on nearby Île de la Cité: “Hôtel-Dieu has all it takes to be pestilential (contagious), because of its damp and unventilated atmosphere; wounds turn gangrenous more easily, and both scurvy and scabies wreak havoc when patients sojourn there. What in theory are the most innocuous diseases rapidly acquire serious complications by way of the contaminated air;
for that precise reason, simple head and leg wounds become lethal in that hospital.
Nothing proves my point so well as the tally of patients who perish miserably each year
in the Paris Hôtel-Dieu…a fifth of the patients succumb; a frightful tally
treated only with the greatest indifference.” LOUIS XVI ISSUES EDICTS
Nothing was done to remedy the intolerable situation until King Louis XV initiated an investigation in 1763. His successor, King Louis XVI, in his first year on the throne in 1775, issued an edict to move the deceased out of the city. The church resisted the notion, which profited from burial fees. Business was good! To reduce the number of burials, the price was increased, something only the wealthy could afford.   Wikipediua In 1780, a mass grave containing over 2,000 partially-decomposed bodies collapsed under the sheer weight spilling into an adjacent basement on Rue de la Lingerie. The event further heightened concerns for public health and hastened the decision to eliminate Saint-Innocents once and for all.  The same year an edict was issued that forbade burying corpses at Saint-Innocents and all other cemeteries within the city limits of Paris. At a time when Saints-Innocents housed over two million corpses, one problem had been solved, but another was created. What to do with the overflowing contents of Saint-Innocents?  MINE RENOVATIONS AND CEMETERY CLOSURES OFFER A COMMON SOLUTION
Mine consolidations were still under way and included the addition of a network of interconnecting subterranean passageways for access. With the cemeteries closed, Police Prefect Lieutenant-General Alexandre Lenoir supported an idea of moving the dead to the newly renovated corridors to be used as an underground sepulcher. The idea became law in 1785. Saints-Innocents was to be evacuated and converted into the public square that has remained to this day, Place Joachim-du-Bellay – more on that story later in this post.  The location for the collective burial ground was a spot designated in popular culture as the Tombe-Issoire within the limestone quarries of the Montrouge Plain outside Paris - more precisely, the suburb of Petit-Montrouge. The region is on the hillsides on the left bank of the Bièvre River mentioned earlier and riddled with limestone quarries at depth. At the time, the commune was outside the city walls of the Wall of the Farmers-General, used primarily for tax collection rather than defensive purposes. It was variously known for its monasteries, religious orders, royal hunting grounds, windmills and, of course, its quarries. Today, there are no famous monuments in the suburb of Montrouge. The major tourist attraction is beneath the quarter!  The location of the Plains of Montrouge outside the walls of the city of Paris  THE CATACOMBS BECOME AN OSSUARY
On April 7, 1786, the grounds of the former quarries of the Tombe-Issoire under the Plain of Montrouge (the burial site of a legendary slain giant named Issoire slain by William the monk) were sanctified in the presence of the church abbots, the architects of the project and Charles-Axel Guillaumot. On November 16th, Monseigneur Leclerc de Juigne and Archbishop of Paris ordered:   “the removal of the Saints-Innocents Cemetery, its demolition and its evacuation,
entailing the turning of the soil to a depth of five feet and the sieving of earth,
with any remaining corpses or bones to be transported and buried
in the new underground cemetery of the Montrouge Plain.”
Cited in Les Catacombes, etude historique, 1861 The Tomb was called the Catacombs of Paris, in French, Les Catacombes de Paris, after the Roman Catacombs. Although Paris’s early limestone quarries date back to the Roman period, the Catacombs do not. And, unlike the Roman Catacombs, they were never excavated for the purposes of burial, only repurposed for burial after the space had been established. The official name for the catacombs is L’Ossuaire Municipal or The Municipal Ossuary.    THE EXHUMATION AND TRANSFER OF BONES
The first transfers of bones from Saints-Innocents to the Catacombs lasted 15 months and continued with the populations of Saint-Étienne-des-Grès, Saint-Eustache, Saint-Landry, Sainte-Croix-de-la-Bretonneries, Saint-Julien-des-Ménétriers and so forth. Continuing to 1814, every cemetery, church ground, crypt and tomb of Paris was nocturnally emptied of its human remains. In total, over six million Parisians were withdrawn and transported to their new “haven of peace” beneath the Plains of Montrouge. The exact number is impossible to determine. The estimate is based on the number of burials up to the year 1860 when the contents of the last graves were transferred to the ossuary.  The enormous transportation of bones was scrupulously ritualized and conducted at nightfall. Torchbearers followed by priests wearing surplices and stoles accompanied funerary carts draped in black sheets while chanting the Mass of the Dead. The poet Gabriel Marie Jean Baptiste Legouvé (1804) described the procession as a “shapeless debris-monument to the departed.”  Wikipedia

The Catacombs of Paris lie some 20 meters beneath the south Paris suburb of Montrouge. The town bears little resemblance to the bucolic royal hunting ground on the Plain of Montrouge. In fact, one must look hard to identify buildings of “old” pre-Haussmann Paris, but they’re there. In fact, you arrive beneath one if you take the Paris Métro at Denfert-Rochereau station, and you must enter one in order to descend into the Catacombs!  A good landmark on the street is the bronze statue called the Lion of Belfort within the square, now auto-roundabout. Theatergoers may recognize it as the backdrop at the beginning of the third act of La Bohème by Puccini. General Pierre Philippe Denfert-Rochereau (nicknamed the Lion) achieved fame by courageously fighting against the invading Prussians in 1870 at the city of Belfort in northeast France. Anxious to put a positive spin on his defeat and looking for heroes of the conflict to glorify, French authorities erected the majestic statue in the center of Place Denfert-Rochereau. By the way, the statue was created by Auguste Bartholdi, the father of the Statue of Liberty. 
   Place Denfert-Rochereau was previously known as Place d’Enfer or the “Place of Hell”, the street of the infamous collapse of 1774. Rue Denfert-Rochereau was formerly called Rue d'Enfer or the “Street of Hell.” “Denfert” and “d’Enfer” are pronounced exactly the same, a coincidence too perfect for the Paris city hall to ignore when they changed the name - an apparent municipal pun. Interesting sense of humor those French. Here the square and the lion on a 1932 map of Paris. Notice the green space immediately to the west of the Place Denfert-Rochereau. It's the Montparnasse Cemetery. After all cemeteries had been banned in Paris for health concerns, several new cemeteries outside the precincts of the capital replaced all the internal Parisian ones in the early 19th century: Montmartre Cemetery in the north, Père Lachaise Cemetery in the east and Montparnasse Cemetery in the south.      LA BARRIÈRE D’ENFER – THE GATE OF HELL
Immediately south of the square is the Barrière d’Enfer – the gate built along the Wall of the Farmers-General around the city. Fermiers-Généraux or tax farmers collected octroi at the tollhouses, an unpopular (and highly abused) tax on goods both entering and leaving the city. The two tollhouses on the long-gone wall still remain - four of 62 surviving ones that punctuated the wall built between 1784 and 1791. Actually several walls surrounded Paris between the early Middle Ages to the mid-19th century, the others being for defense rather than tax collection. Here’s an epigram on the octroi that rhymes in French: “To increase its cash
And to shorten our horizon
The Farm judges it necessary
To put Paris in prison” You can actually see the outline of the ancient wall on a Metro map of Paris by tracing metro lines 2 and 6, while wide boulevards replace the former fortifications. For those interested, the Rotunda at Parc Monceau on the north side of Paris on the Right Bank – originally called Barrière de Chartres - is an elegant tollhouse of the few that remain on the barrier wall.    Back at Denfert-Rochereau, two neo-classical tollhouses on the long-gone wall still remain. The easternmost building (right in the photo) is reserved for the Inspector General of the Quarries and is the site of entry into the catacombs – our entry into hell. The westernmost building (on the left) houses offices of the Directorate of Roads and Transport. Notice the Lion of Belfort on a pedestal in the center of the public square.     In spite of the nightly rituals of interment, the Catacombs were unknown to the public at large until 1810 when the second General Quarry Inspector, Louis-Étienne François Héricart-Ferrand, issued the first brochure that advertised their presence and began drawing curious Parisians into their depths. Prestigious figures that followed included Francis I of Austria in 1814 and Napoleon III and son in 1860. Today, the Catacombs have become a major tourist attraction and is managed by the City of Paris Cultural Affairs Division in association with the Carnavalet History of Paris Museum.
During the 1830’s to 1840’s, excursions were not limited to just the Ossuary and led by mine overseers “who guided them as struck their fancy; inevitable abuses occurred, the quarry galleries as well as the ossuary were damaged by unscrupulous people and visitor lost their way.” (Emile Gerards in Paris Souterrain, 1991).  OUR DESCENT INTO THE CATACOMBS
We arrived at the east pavilion of the Catacombs well before the opening time of 10 AM and found a line already forming at the entrance. Both Parisians and tourists alike want to be amongst the first 200 visitors allowed in, and we were no exception.  To enrich our experience, since tours are delivered in French, we arranged for an English-speaking guide and most affable fellow from Ireland (although audio-guides are available French, English and Spanish). He was extremely knowledgeable about both French and world history, and spoke four or five languages, so he was able to translate the 18th century signage in the Catacombs.  After purchasing our tickets, we descended a tight, spiral staircase of 130 steps into a dimly lit gallery 20 meters below street level – equivalent to a five-story building.  

The entire tour covers a distance of about two kilometers and winds through a dimly lit labyrinth of galleries and interconnecting tunnels beneath the streets of Montrouge. The official brochure states that the average duration is 45 minutes, but we easily took twice that. There is a constant temperature of 14º C (57º F).
Be forewarned, as there are no toilet or cloakroom facilities within the Catacombs. Lastly, as stated by the official Catacombs Visitor's Guide, the tour is unsuitable for people with heart or respiratory problems, those individuals of a “nervous disposition” or claustrophobic, and young children. There is no disabled access to the Catacombs. The experience is quite macabre to those unaccustomed but incredibly fascinating in regards to Parisian history, geology and paleontology.

La Visite aux Catacombes, Aquarelle, 1804-1814, Musee Carnavalet Visite aux Catacombes
Reproduction d'une gravure anglaise, 1822, Carte postale, vers 1900, Collection Roger-Viollet  LA MER À PARIS - THE SEA IN PARISBetween street level and the Catacombs, visitors travel back to the Lutetian age. At the bottom of the spiral staircase and before entering the Catacombs proper, visitors are guided to an exhibition entitled “The Sea in Paris – 45 Million Years Ago,” which ends December 31, 2014. The new installation “highlights a little known aspect of the Catacombs – their geological heritage, a real treasure-house in the subsoil of the capital.” (Of course you can read it all in my post Part I here). A series of murals in both French and English takes you on the “journey through space and time” with paleographic maps, chronological profiles, photographs, drawings and engravings that beautifully demonstrate the evolution of the Paris Basin and the Lutetian Sea. In addition, there’s a detailed description of the Left Bank’s limestone quarries and the circumstances that led to their repurposing as an ossuary.  One of many geologic maps and cross-sections on display that depict the tectonic and geologic evolution of the Paris Basin and the region of Paris. My red arrows identify the underground limestone quarries (calcaire carriers souterraines de calcaire) of the Left Bank, south of the River Seine and the open air Roman quarries carrieres a ciel ouvert), also on the Left Bank, along the River Bievre. After departing from the exhibition, the tour continues through a long interconnecting corridor. It seemed like a long distance to the Ossuary, but with narrow walls and no horizon for perspective it's deceiving.   Corridor leading to the Ossuary portion of the Catacombs   LES SCULPTURES DE PORT-MAHON - THE SCULPTURES OF PORT MAHON The Catacombs is filled with many curiosities. Perhaps the most unique and popular is the sculpture created in 1782 by Beauséjour Décure, a discharged soldier who had been enrolled in the army of Richelieu during the re-conquest of Minorque. Although few details of his life are known, once discharged he worked in the quarries. During breaks, for five years Décure chiseled a replica of Port-Mahon, the principal port of Minorque, out of limestone. Wanting to make his creation more accessible, he was killed by a cave-in while opening an access stairway to his model. Currently, the sculpture is not included in the protective measures of the Ossuary and is threatened by a real estate project overhead. "C'est la vie."    
LE BAIN DE PIEDS DES CARRIERS - THE QUARRYMEN'S FOOTBATHThe first geological drilling undertaken in Paris (actually under Paris) was carried out by Héricart de Thury in 1814. Dubbed "The Quarrymen's Footbath", the well contains crystal clear groundwater that has percolated into the drilled-depression. The only way to detect its presence is to step into it. One can only guess the mischievous pranks guides carrying candles and torches must have had with their tours. The water was subsequently used by quarry workers to mix cement required for the Catacombs.

Limestone is more or less finely porous and permeable to water. At depth - from a few centimeters to several hundred meters - and depending on the series of geological strata and the relief, the rocks are saturated with water. This forms a series of superimposed phreatic zones or aquifers, separated by impermeable argillaceous (clayey) rocks. The water table represents the first phreatic zone to be reached when a well is dug such as the Quarryman's Footbath. Its surface fluctuates with the whim of the rain or even the nearest river. By the way, the principle of artesian wells was demonstrated in 1828 by Héricart de Thury and later applied in the drilling of the Grenelle well in the 15th arrondissement of Paris. 

Bains de Pieds des Carrieres, Catacombs Brochure, DAC/Ch. Fouin

You’ve officially entered the Municipal Ossuary having passed beneath the engraved, limestone lintel that declares “Stop! This is the empire of death”. Of course, tens of thousands of visitors every year are hardly dissuaded by the ominous warning. In actuality, this is the “new” entrance, the original being at the end of the ossuary. Visits to the ossuary begin with the most recent bone transfers.

The limestone quarries have been closed to the public since 1955, but the Catacombs have remained open. At the time that Guillaumot was strengthening the tunnels beneath Paris, King Louis was closing the overcrowded cemeteries. The exhumations went on for years - long after the King lost his head in the French Revelation in 1793 - until all the bodies had been reinterred in a new realm – this, the Empire of the Dead.

The black tar line on the ceiling was traced as a path to follow by candlelight to prevent 19th century visitors from losing their way in the maze of galleries. An example of how easy it is to get lost is told by the tale of the porter Philibert Aspairta, who entered the quarry alone in 1793 and lost his way. He was found by a survey crew 11 years later and given a proper burial where he had been discovered.

In the words of L.F. Hivert in 1860:

“We etched a broad black line commencing at the base of the staircase and meandering all the way through this vast labyrinth. A stray visitor, provided he has light, need only follow this Ariadne’s thread to find the door. From place to place, the line bears an arrow pointing towards the exit door, as the flow of a river is marked on a map.”
Immediately within the entrance to the ossuary is a stele (funerary monument) dated 1810 that commemorates the establishment of the Catacombs. It was moved from the original entrance when the ossuary was expanded.

   “Catacombes established by order of Monsieur Thiroux de Crosne, Lt. General of Police, and by Monsieur Guillaumot, Inspector General of Quarries, 1786. Restored and improved by order of Monsieur Frochot, Secretary of State, Chief of the Department of the Seine, by Monsieur Hericart de Thury, Chief Mining Engineer, Inspector General of Quarries, 1810.” BONE STACKINGIn the first years, the Catacombs was a haphazard repository, but renovations in 1810 transformed the underground ossuary into the visible mausoleum (and tourist attraction) that it is today. Skulls and femurs were stacked in repeating patterns in total anonymity, while funerary decorations such as monumental tablets, archways bearing inscriptions, warnings and even poetic verse were installed to complement the walls of bones.     WALLS AFTER WALL LINED WITH BONESAlthough some sections of the Ossuary contain a haphazard array of bones, the tour only reveals those neatly arranged in cranium-studded friezes of skulls (maxillae only, no mandibles or teeth), femurs and tibias. Both macabre and somehow strangely romantic, I could only imagine what fantastic tales of life in Paris the speechless skulls would tell - having lived during reigns of King Louis XV and XVI, the French Revolution, and the Reign of Terror and its infamous guillotine.     The City of Light's 12 million residents live in the world above, while below the streets in the Empire of Death, 6 million remain at rest. There are many signs within the Ossuary. Some record the street on the surface above, often with names that since have been changed. Some document the date | Impressum