Paris invisible : Les secrets de la Cité des Ombres | Trésors du Patrimoine

Paris invisible : Les secrets de la Cité des Ombres | Trésors du Patrimoine

Paris needed its subsoil
to be born, since for a city to develop, water is necessary. So, the Seine is where what will
become Paris will be established. And the good news
is that in the surrounding area, there are materials that can be
used for permanent construction. So it is the exploitation of these subsoils
that has allowed the city to develop. And today, the city can function every
day thanks to the use of its underground infrastructure, because it has
developed technical galleries there. It’s the subway, it’s the sewers,
it’s tunnels for telephone cables, it’s tunnels
for electricity, it’s tunnels for
district heating, for air conditioning. So today,
without these technical galleries, the city would be a huge traffic jam,
since several million people take
the metro every day. It would be a great silence,
because even though there are satellites,
there are still telephone cables to
carry communications. It would be dark, because electricity
also runs through basements. Therefore, Paris could not be
a modern city if its underground spaces were not used
by all these technical spaces. Hidden in the depths of the City of Lights
is its twin sister, the City of Shadows. Made up of different
independent networks extending over several thousand kilometers,
these galleries intersect or overlap without ever meeting. Among these main systems, the
largest and undoubtedly the sewer system. Stretching 2,600 kilometers,
equivalent to the distance between Paris and Moscow, it runs directly under the sidewalks
and overlooks the approximately 400 kilometers of subway tunnels,
whose vaults reach an average depth of 10 meters. Finally, at around 20 meters,
we find the deepest and oldest of all these networks,
that of the quarries, which was an architectural structure that lasted until the end
of the 18th century and which can still be visited today. The first mining operations,
what you need to be aware of, were open-pit. When the Romans arrived
in what would later become Paris,
they were fortunate to find limestone under what would become today the
left bank, and gypsum exclusively under the right bank. Gypsum is the result of
lagoon sedimentations that took place 35 million years ago. The material that settled
crystallized into gypsum. And limestone was formed
by sedimentation in the oceans 45 million years ago. And when you look closely at the limestone,
you can see fossils, you can see small seashells. So, when you have the chance to visit
underground quarries, even if it’s just by visiting
the catacombs, you’re in a solidified ocean, so to speak. At the end of the 12th and beginning of the 18th centuries, underground mining began
for reasons of, I would say, economics and time. Because if we wanted to continue
open-pit mining, we had to strip the land
above it. Whereas the simplest way
was to go underground directly into the limestone
or gipsum layer that we wanted to exploit. From the moment we start these
underground operations, we use a type of mining
called pillar mining. That is to say, we dig more
or less parallel galleries which we intersect with more or less
perpendicular galleries and we leave in place large mass vises which are
these turned pillars which will support the land above. And the quarrymen, from the end of the 15th,
beginning of the 16th century, will have the idea no longer of exploiting the limestone over the entire
height of the limestone which can represent four,
five meters in height, but only on the beds which will sell best. So, as we
exploit the site, we fill in behind us the void we are creating
with mining waste and we maintain these blockages with hags. The hags are small
walls made of dry earth. So, an operation by hague
and bourrage, it is a succession when we look at a plan of hague, bourrage,
hague, bourrage, hague, bourrage. We replaced all the void that we
dug in the limestone with this hague and bourrage. At the turn of the 15th and 16th centuries,
careers became specialized. Some quarrymen will prefer
the exploitation of soft stones, intended for the creation of sculptures,
while others will favour those of hard stones,
more suitable for the construction of columns or steps. Thus, a specialized quarry will be able to
supply several construction sites, but a construction site will
require different types of stones and will therefore be supplied
from several quarries. Here, we are
at the level of the Cauchin hospital. The Saint’s team career
is here, the staircase is here. It’s all of that, all that little network,
Royal, below too, and rue de la Santé, up to about here. We have 1,500 meters
of underground access. I discovered the quarries in 1976. And Mr. Clément,
who was the president of the association at the time,
wanted to preserve a small part of the quarry to showcase
and show the public what the extraction of building stone was like. The quarry worker’s job was
dangerous and not very well paid. There was a time when people who came
from the march, from the Creuse, from the Limousin, came up to Paris. There were often incidents
and many quarrymen got out during transport because
there was no hospital nearby. This also explains the creation
of the hospital above the quarries. It was a donation from Godefroy
de la Tour in 1613. He gave the field to the Capuchin. And Father Denis Cochin bought three
houses to care for the poor and injured quarrymen. So, as
people were treated there, it became known as the Cochin Hospital over the centuries. The
fountain located under the Cauchin hospital is actually a blind well,
with no access to the surface. This construction aimed to measure
variations in water level with its graduated low-water scale in order to
study the phenomenon of groundwater fluctuation. So here we have the outline
of the fountain, a drawing of the fountain at 1:1 scale. It was roughly taken at
the desired size and then refined on the site. So, you have the numbers, the stones. The water is here. So here, there’s the whole outline
and here, the steps. The compass point is
still there in its original position. It’s rare; we haven’t found
any plans like this. None. So that’s why it was classified. So, here is a souvenir from Notre-Dame. We have a replica of the entrance
to the portal of Notre-Dame. According to a report by Colbert,
the nave of Notre-Dame was built with stones extracted from the
Carrée des Capucins and the Val de Grace. So this is a mark
made with soot. This allowed the quarryman to go
to the front, that is to say to the work they had to do and to get
out of it, since you have to imagine that at the time, we have a candle where they
could not see, but at the very most, you can see nothing. So, he oriented himself in the sky like that,
and he followed the lifeline or Ariadne’s thread, as you prefer. So, we’re trying to revive
a hague the old-fashioned way. We fill the cavity first and then
we finish with the rubble stones to close it. I’ll have to trim it here.
I’ll try a little bit here. So. Well, now, it’s been 27, 28 years since I’ve been involved with it. It’s part of the association. It’s a passion because we’re all
practically from the underground world, whether it’s caving, mineralogy and everything. And then, we really realized that
there is a truly significant heritage. It is time to
preserve and save it. The memory of Paris,
that’s really what it’s about: preserving it. It’s a priority. The quarries, when they were being
worked, were under the countryside. And a few centuries later,
the city of Paris expanded so much that it came to be built
above the void of old quarries. And the aging of these quarries,
plus the mass of buildings that have been added on the land that was
undermined, means that collapses have
begun to appear and have begun to impact the safety of the city. And for example, in December 1774,
there was a major subsidence that took place north of the Place d’Enfer Rocherot,
which really impacted several buildings that collapsed and
suddenly disappeared from the surface of Paris. In 1778, for example,
at the level of Meigny-de-Montand, there were seven people
who suddenly disappeared into a sinkhole and were swallowed up,
truly swallowed by the Gips quarry, whose underground void had just
risen to the surface. And the last major collapse
in the Paris region was in June 1961, in Clamart. There was a whole area between Clamart
and here in Les Moulineaux that collapsed. There, it was a collapse of a
quarry in Crée and there were 21 deaths. But when you look at aerial photos
of this latest major quarry accident in the Paris region,
all the ground is cracked. It looks like we’re witnessing
an earthquake. When Louis XVI became aware of the peril threatening Paris and the extent of the safety problem caused
by the collapses of its subsoil, he established the General Inspection
of Quarries on April 4, 1777. Then, he appointed a brilliant
architect, Charles Axel Guillomo, to head it, tasked with mapping, designing
and consolidating this network. The latter, who could have simply
created shapeless pillars to accomplish this task, will begin to work
underground using the same methods as for the royal buildings. Thus, he uses
sophisticated architectural techniques to create beautiful massifs,
often embellished with piles of loads and other beautiful features. And this architect, he carried out all the reinforcements
while the city was functioning above. And the principles he adopted,
therefore, of making masonry blocks directly above the facades of the houses,
of building under the main thoroughfares which were wide enough,
of providing two parallel galleries intersected by transverse ones, of
requiring that everywhere, the workers could pass upright with a wheelbarrow. Therefore, all the principles he adopted
were followed by all his successors from the creation of the service
in 1777 until 1909. For example,
when you are in the galleries of Carrières,
you see two main types of inscriptions which are either names
that we will assimilate to street names or names of locations
in relation to the surface. And we also have a trinomial coding,
an order number, an initial, a year. This is to identify each
of the pillars and to be able to say, a few years later or 50 years later
or 100 years later, that pillar which has given way or which did not
prevent a problem or which is cracked now, is a pillar which
was built under Guillermo. We can still find the attachments,
the architects’ drawings which are in the archives which correspond
to the construction of this pillar. All of this is something that
was developed by Guillermo. It says there: Rue des Bourguignons
under the wall of Val de Grace. So, it’s a mapping of the subsoil
in relation to the surface. At the time, the Rue des Bourguignons
ran alongside the gates of the Val de Grace. The interesting thing is that
there used to be a kind of lily there, and it was destroyed during the revolution. The only fleur-de-lis that have been
preserved, there are not many under Paris, it is because they were
hidden at the time by fill or other. There is a very fine consolidation
by Charles-Axel Guillaumeau, dating from the creation of the inspection in 1777. Logé is here and the
29th phase of consolidation of the surroundings, that is to say
under the Cochin hospital. And at the same time,
we are faced with another problem, which is a sanitation problem in the
city around the Cemetery of the Innocents. The Cemetery of the Innocents was one
of the oldest cemeteries in Paris. And at the end of the 18th century,
there began to be complaints from local residents because so many
bodies had been piled up in this cemetery. Because you have to imagine,
when you dig a grave, you put a body in, you put the earth back on top. So, we raise the earth by a few millimeters,
let’s say. But when you do that for centuries
and centuries, by the end of the 18th century, the cemetery floor was 2.50
meters above street level. And all those bodies that were
rotting in the cemetery, when it rained,
the water seeped into the cemetery, fed an apreuriatic and
unfortunately, the city of Paris was supplied a lot of
water through the wells. So, there were infections. Locals who had cellars
near the Cemetery of the Innocents noticed that the milk curdled
on its own, and the wine turned to vinegar. They avoided touching the walls because they
could see liquids seeping down them. The air was foul. And in fact, in February 1750, in 1980,
there was a mass grave which literally exploded and whose contents spilled
into the cellar of a private individual, on rue de la Lingerie. And at that moment, it was decided
to close the Cemetery of the Innocents. So, we looked for a new location
and it was Charles Axel Guillaumeau again who solved the problem by finding
a quarry outside of Paris. At the time, this quarry
was under the Montrouge plain and it was abandoned. And he will decide to develop this quarry
into a municipal and general ossuary for the city of Paris. In 1785, they began to exhume bodies
from the Cemetery of the Innocents and to transfer the bones at night to a
temporary storage place before they could actually be brought to the catacomb. Indeed, the Church is resisting somewhat. She is deprived of the
exclusive control over death. Finally, the Church eventually accepted
the creation of this municipal ossuary and in April 1786,
a part of the quarries which would be used for this purpose as
a municipal ossuary was officially consecrated, quarries which are located at the place called
La Tombe-Issoire, that is to say in the plain of Montsouris,
the current catacombs of Paris. The transfers began as early as April 1786. The bones were dumped through
wells which were Carrier wells. First the Cemetery
of the Innocents was transferred there, and then, during the years 1787, 1788 and up to 1989,
other urban cemeteries which were also declared harmful. This is the case, for example,
of the Sainte-Croix de la Bretonnerie or Saint-Méry cemetery. We are really in the cemeteries
of central Paris. The revolution breaks out. Until now, it has been a site
for secondary burials. The old
cemeteries that are closed are being transferred there. With the victims of
the revolutionary events, the catacombs will become for a time
only a primary burial site, since
some of these victims will be buried there. The reason the main entrance to this place,
already known as the Catacombs of Paris, is monumental
is that in 1809, Louis Étienne Héricard de Thury,
the second Inspector General of Quarries and successor
to Charles-Axel Guillaumeau, decided to open
the municipal ossuary to visitors. However, the aim of this choice is
not to make it a place of macabre attractions, but rather to allow
the families of the victims of the Revolution,
as well as those of the deceased whose bodies were transferred to the catacombs,
to be able to gather in the burial place of their ancestors. Éricard de Thury will therefore design a place open to visitors. He was the one who initiated
the layout of the catacombs, the arrangement of the bones,
but also all the decorative elements that punctuate
the Catacons’ journey. Obviously, these decorative elements
will evolve after Ericard de Thury and with his successors,
but he is the general designer of this cemetery. And it was indeed the project of a
secular cemetery that was put in place by Éricard de Thury. However, Éricard de Thury was
a staunch Catholic monarchist. So this decision
is truly philosophical. He wants to create with the municipal council
a place for philosophical strolling that allows the visitor to become
aware of their mortality and to reflect on the
inevitability of the end. That is why all the elements
that have been chosen, the pillars, the inscriptions
that will be placed in different places along the route,
are references to Antiquity, a heroic, glorious Antiquity,
that of the Egyptians, that of the Romans, that of the Greeks, which, ultimately,
is disconnected from a Christian religious message to allow this
much deeper reflection on death. This type of display cannot be found
anywhere else in the world. This means that the majority of bones
from the various Parisian cemeteries are placed as
fill in the different cavities created by the quarrymen during
the quarrying operations. And then, these bones will be blocked
by the hags, the walls which are made up of long bones, essentially the tibias,
the femurs, self-locked by the arrangement of the bones into which the skulls will be inserted
which will form more or less explicit patterns. Religious motifs being quite rare,
here we have a cross which is drawn by skulls, but it is an originality. The majority of the motifs are
geometric patterns or chevrons that mark the upper part
of the hags with these sets of skulls. So, we really have here an arrangement
that recalls the original purpose of these spaces as a quarry
and their repurposing as a municipal costume shop. The Catacombs are the burial place
of many important figures in French history. From the cemeteries that were transferred,
we know who was buried there, so we know who is ending up in the Catacombs. We could cite personalities
in all fields, whether it be the artistic field,
François Rabelais, Racine, Simon Vouet, Jacques Stella. In the political sphere, Robespierre,
Danton, Hébert, and Marat rest in the Catacomb. In the historical field,
Madame de Pompadour rests in the Catacomb, Madame Elisabeth. What is a little disturbing
is to imagine that ultimately, all these bones are mixed together,
and that perhaps the bones of Madame Elisabeth are
mixed with those of Robespierre, Fouquier-Tinville,
or a simple beggar, since a large part of the deceased who are
in the Catacomb are anonymous deceased. And finally, this is where we are faced with
the true temple of humanity, which is that whatever status
you may have had in your life, the bones are all placed
on the same level in the catacombs. And that is precisely the line of thinking that
Éricard de Thury wanted to implement. We are standing here in front of a group of sculptures, and it is one of the workers of this
General Inspectorate of Quarries, Antoine Descure,
about whom little is known, who is behind the sculptures
that you can see behind me. Indeed, during these breaks,
and especially at lunchtime, Antoine Descure sculpted three
monumental views in the rock of Port des Baleares, Menorca,
in which he had been taken prisoner at the time of the conflict
between France and England in this region. Having returned to France and settled in Paris,
Antoine Décurre became a quarryman, and so it is partly in memory of this
deportation to Minorca that he sculpted these ensembles which today
constitute curiosities. These popular works obviously do
not have a major interest in terms of art history,
but rather serve to remind visitors of the initial origin of the ossuary,
as well as the cessation of quarrying. Even today,
Décure’s sculptures are a highlight of the Catacombs visit,
and have even given their name to the Parisian underground district
in which they are located, since they have been called
the Portmarbe quarries ever since. We are at the highest point
in Paris, on the public road, since we are at the top
of the Belleville hill. And we are here inside a
building called a “regard,” which is part of the system that supplied
the old fountains of Paris for at least five centuries. During the Middle Ages,
Christianity reached its peak in the West, and the site of Paris
saw the establishment of large abbeys. And these religious communities, in the past,
were the ones who had the vocation of caring for the sick,
therefore with great needs for water. And it so happens that the abbey
of Saint-Martin-des-Champs and the abbey of Saint-Lazare owned fields, orchards, and crops on the hill of Belleville. And they had noticed that everywhere on this
hill, water was seeping out from all sides. And these religious men had this idea
of ​​saying: If we could drain these waters from our land,
since we are on a hill, it would be easy, by following the slope,
to supply our establishments located below. So, they dragged the hill along
like one drains a field. And the first works carried out
in the surrounding area were done from the 12th century onwards. So, all the water
captured on the heights of Belleville is called the Northern Springs,
because we are north of Paris. And from the 12th century to the 17th century,
in the fountains of Paris, there was only water captured here. It was therefore to protect these
strategic points where the waters gathered that small
stone buildings called “regard” were built. Their main purpose is to keep these
systems operational, but also to allow access to the system for maintenance
and monitoring. This gaze is called the
lantern gaze, because of the small capital that is at its top. In architecture, a lantern is called a lantern
and brings both air and light into the interior of the structure. And
we can say that we are dealing with a small monument of
French Baroque architecture. You can see that it’s all curves
and counter-curves, because you see, here we have a real little temple
dedicated to water which is there solely to protect the step that. But it must be understood that nobody,
nobody entered these structures, except for the fountain workers
and the municipal council. Therefore, a very high-quality work
which clearly demonstrates the importance that was given to the Parisian water supply. So here, it had the advantage of being
fresh water, since it traveled protected from light
in underground pipes. It was rainwater that was flowing
through the fields and crops. Now the city is sealed off. There’s asphalt everywhere,
concrete everywhere. The high-rise buildings you
see around all have multi-level underground parking lots,
with electric pumps that further lower the
groundwater level. So, as a result, in the few
remaining works, only a few drops
still manage to seep through. So, the little water that
still flows through the drains today ends up in the sewers. Here, we are 3 meters underground. The sewers are on average
3.5 meters deep in terms of elementary sewers. Large collectors can descend
up to 50 meters, but this is very rare. This sewer system dates
from the mid-19th century. In fact, there were very
few sewers at the time. There were about a hundred
kilometers of sewers. Most of the wastewater was
in the streets and people were in constant contact with this wastewater. And so, this generated diseases,
notably cholera. So, a cholera epidemic started
in 1832 which caused the death of 19,000 Parisians. To prevent these disasters from
happening again, we will still consider creating a modern sewer system. Therefore, from the time
Napoleon III came to power, Napoleon III asked Haussmann
to take charge of the modernization of Paris. So, the real creator of the sewer network
is Eugène Belgrand, who is an engineer who was hired
by Prefect Haussmann to create the Network of Tastes. In addition to creating this sanitation network, he also
created all the drinking water supplies
that allowed Parisians to have water in their buildings. So, little by little,
we will start to create a significant sanitation network. And from 1892, so a few years after the construction
of the network, there was a law called the “all-sewer” law,
which obliges every building that has a sewer in its basement
to discharge directly into the sewer system. The 2,600-kilometre network of tunnels
that make up the sewers is entirely open to visitors. This system has the particularity of being
both unified, meaning that it collects and gathers
both rainwater and wastewater, but also gravity-fed,
since it is the slope of the sewers that allows the water to flow
towards the treatment plants thanks to the force of gravity. 150 years ago, when the network was created,
individual equipment consisted of overalls,
a pair of boots and a cap. Today, the service has greatly
improved the protection of staff and we are very well equipped
to be able to descend safely into the ego network. One of the main dangers
is toxic gases. So, we have gas detectors,
full face masks and masks, what we call escape masks
which allow us to ascend safely with a
small reserve of oxygen. I suggest we go into a
basic sewer to give you a small idea of ​​the size of these structures. We
‘ll stop here and talk about what are called
special connections. It’s the connections,
it’s the link between Parisian homes and tastes. The private connection is
a gallery accessible from the cellar. The Parisian network
has more than 100,000 of them. Here we arrive at a
main collector and a desilting basin. This main collector is three
kilometers long, two meters deep
and it is cleaned by the machine you see in front of you
which is called a boat-van. The principle of the boat-van,
the principle of the chasing effect. The valve takes the exact shape of the sewer,
causing the water level to rise behind it. When the water accumulated,
we opened the valve at the bottom and the water accelerated its pressure and I pushed it all the way to the
stable basin where it was then collected. What is interesting to know
is that the sluice gate boat has been used for 150 years and is still in use in 2021. That is to say, the inventors of this
technique, Belgrand in particular, made something so
effective that it is still used today. The principle of the sewer system is a bit like the stream, river, and stream principle, meaning that the elementary sewer flows into a secondary collector which itself flows into a main collector and which in fact ends up in outfalls which are gigantic collectors which go to the treatment plants where today they are treated and released back into the environment. We have arrived here at a station
measuring pollution on the Seine. One of the three stations that exist
around Paris and the inner suburbs. It allows us to measure
different types of pollution. Dissolved oxygen, conductivity,
hydrogen potential, ammonium, turbidity, etc. We also have systems that
now allow us to collect rainwater to avoid releasing as much of it as possible into the Seine. Today, the sewer network is 150 years old and should be able to continue for a long time, while continuing to modernize and keep up with the evolution of techniques, but always operating on the same principles. The first
metro works were in 1898. And above all, there was an engineer enamored with
technology and modernity, Fulgence Bienvenue, who would overturn
the ideas received until then. The network we know today
is fundamentally linked to the work he accomplished. It will adopt the Electricity fact
for attraction, for lighting, for maintenance and indirectly
for signaling. He will also start from a second idea,
which is that the network will become more complex, he plans this from the start, and therefore,
it will be a matter of interconnecting all the lines together. He knows that the biggest problem
in building infrastructure is expropriation. So, we’re going to fix the problem. The city of Paris owns
its road network. The metro will go under the road.
Point. And he carries out his plans with his colleagues
from the water and sewage services who themselves, when they carry out
new works in the field of sanitation, will take into
account the metro projects. So, in fact, this organization and
management of the sequence of work will be important
and will also allow, in its construction, for planning for the future. Given that we want the metro
to be ready for the 1900 exhibition , we need to act quickly. And to make it quick, we’ll simply
close the roads to traffic, block the streets, rip up the streets,
and build in open trenches. So, for example,
let’s imagine today the Rue de Rivoli closed along its entire length, to allow
the construction of metro line 1. That’s what was done. So, the operation of the metro
began with the opening of line 1, on July 19, 1900,
at precisely 1 p.m. That’s how it is. The subway was not built
by the company that operates it. It was built by the city
of Paris, which had grand plans. And the company that operates it, which is a concessionaire, the Paris Metropolitan Railway Company, as in 1900, it is not completely certain that this metro will work as well as we hope, it will choose rolling stock that is just necessary for the start of operation. But the subway will work well. It’s going to work even better than expected. And we quickly realize that this
first generation of vehicles and operating methods is
outdated and will have to be changed. And then, this change
was precipitated on August 10, 1903, at the Couronne station. There will be 84 deaths from asphyxiation,
following a series of incidents that constitute a catastrophe. And this catastrophe
is the fire of two train carriages based on a relatively
trivial electrical incident. So, it’s going to be,
some will say, the Titanic of the subway, except that the subway itself didn’t sink,
so it survived this catastrophe. But this will require a complete
rethinking of how this new infrastructure is operated, by multiplying
access points, completely renewing the rolling stock for
metallic equipment, and reviewing the operating conditions. And
so, shortly before the First World War, we had a metro running with
the most modern equipment possible at the time. And this equipment, it was really
well designed as well as the operating methods. Because the
operating concept put in place at that time, it lasted until the
1970s, that is to say more than 60 years, and even a decade more for
the rolling stock, which only came in 1983. In the 70s, the increase in the electrical voltage
of the network allowed the development of many modernizations which
gradually formed the metro as we know it today,
such as the implementation of a magnetic ticketing system or the
centralized regulation of traffic. All these advances correspond to the arrival
of computer technology in the operation of an old network that is being modernized. Then, since the 2000s,
the period of automation began, with the opening of line 14,
which is the first fully automated metro line in the world. And so, we will find
technological solutions that will allow us to meet a single need,
which has been the same need since 1900. Increase transport capacity,
meet demand, because we cannot refuse travelers. There is no one at the entrance,
there is no bouncer like in a nightclub who says: Yes,
you can come in, you can’t , we take everyone. Sometimes they even arrest people
who don’t pay, imagine that. That’s very bad. But we have to meet
the demand. So, we will continue to work on
the techniques and in the meantime, progress has developed and the first
shields and tunnel boring machines that were developed have been modernized. So, in fact, the tunnel boring machine
is a machine that can go up to 50, 100 meters long, that is,
roughly, the length of the subway stations in Allée 14 today. The work progresses
by digging in front of it. Are you talking about this evening, as we install,
gradually, we realize the masonry
and support problems of the work that is being carried out. And we clear the land behind it. This will be an extremely
important step because afterwards, it will be the widespread use
that we will develop. Long before World War II,
Paris lived in fear of German revenge and their massive use
of poison gas, which had been developed during the previous conflict. To anticipate a potentially
dramatic event, it was therefore decided to build
numerous underground shelters adapted to this threat. These gas-tight shelters are
all characterized by roughly the same type of construction. An airlock is needed to ensure
that no toxic gas enters the building. These shelters must be
self-sufficient in operation. And so, there is a generator
set there to ensure the continuity of electricity. And if this generator breaks down
or if there is no more diesel, there are cyclone fan systems. So, people get on bicycles,
pedal and thanks to the dynamo, restore the electricity,
or there are crank systems and in addition, turn a fin
in pipes which will circulate the air which will pass over
carbon filters to purify the air. Another characteristic of these shelters is that
they must always be under positive pressure relative to the outside air. That is to say, if this shelter ever cracks
due to bombing, it must be the internal air
that escapes and not the contaminated outside air that enters the shelter. From the moment there were a few
bombings of Paris within the city walls, the inhabitants spontaneously sought
refuge, in fact, in the cellars. They go on the subway, but they
also eventually go to the quarries. The distinction is that we are talking about three
shelters in the subway because they are gas-tight shelters. The rest are
underground stations that have become shelters for the population. But 40,000 shelters
were set up in the cellars of Paris. So, the majority of the population
went down into the cellars of Paris at the time of bombings or at the time
of alerts, especially during the Second World War. Do you remember? That was yesterday. The enemy was still there. He spied, he prowled, he wanted to know,
he tortured, he killed, he murdered. No precaution was superfluous. During the historic hours
of the insurrection, underground, in the heart of the capital,
beneath the deep catacombs, Colonel Roll had his
command post, dictating his orders. Roll Tanguy, from August 20 to 25, 1944,
came to set up his command post in the shelter at Place
d’Enferrochereau, which was a passive defense shelter
for the Paris City Water Service and the Metro Service. And the little anecdote goes that every
day, there was a German who would make a phone call and get hold of the
telephone operator at the air-raid shelter. And the German asked, “No problem,”
and the telephone operator said, “No, no, there is no problem.” While Roll Tanguy,
during those five days, coordinated the
Paris insurrection from the underground. From the Île-de-France region and open
the road to Paris for the victorious Allied armies and welcome them there. Colonel Roll, the regional commander. And we can say that the Liberation of Paris
came from the basements of Paris, since Roll Tanguy’s HQ was
in this shelter which is established at the level of the quarries and which is in communication,
of course, with the catacombs and with a number of exits. And that’s why Colonel
Roll Tanguy had chosen this shelter. And in addition, in this shelter
there was an independent telephone network , plus the network
of the ancestor of the RATP which made it possible to follow the entire arrival of the liberators from the landing. The underground environment is fragile
because the slightest modification or degradation means that
no authority realizes that it is a historical environment. These are individuals
or associations trying to raise awareness among
government agencies that Paris is not just a functional entity. There is also, there is an aesthetic,
there is a history, there is a culture. It’s a set. Today, many documents are still to be found in the archives and entire sections of the history
of Parisian underground remain unknown. Only a few fractions of the
underground quarries have been protected, such as those of Capucins,
Val de Grace or Port Mahon. But a classification measure is not
a safeguarding measure and even the ossuary is not listed
in the supplementary inventory of historical monuments. Danger looms over the City of Amber,
and the dedicated guardians of the underground heritage must continue to watch
without ever lowering their vigilance.

Sous la Ville Lumière, une autre Paris respire — celui des ténèbres, de la pierre et du silence.
Amoureux de la France et du patrimoine, ses trésors n’auront plus de secrets pour vous 👉 https://bit.ly/4dnI1h1

Chapitrage :
00:00 La Cité des Ombres – Paris souterrain
03:00 Les carrières de calcaire et de gypse, fondations de la ville
08:00 L’inspection générale des carrières, une invention du siècle des Lumières
14:00 La création de l’ossuaire municipal et la naissance des catacombes
20:00 Les égouts de Paris, artères cachées de la capitale
30:00 Le métro : un réseau né du progrès et des révolutions industrielles
45:00 Les abris souterrains de la Seconde Guerre mondiale
50:00 La préservation du patrimoine enfoui

Sous les pavés, un autre Paris s’étend sur des milliers de kilomètres : carrières, catacombes, égouts, tunnels et abris militaires tissent la toile invisible de la capitale.
De la pierre calcaire de Notre-Dame aux galeries des catacombes, ce film explore la Cité des Ombres, ce double souterrain de la Ville Lumière.
À travers l’histoire des carriers, des ingénieurs, des résistants et des bâtisseurs anonymes, se dessine une épopée fascinante : celle de la ville sous la ville, reflet obscur mais essentiel du Paris que nous connaissons.

Titre : La Cité des Ombres – Les secrets de la Ville Lumière
Série : Paris au pluriel
© Tous droits réservés – AMP

#Paris #Catacombes #ÉgoutsDeParis #MétroDeParis #CarrièresDeParis #Patrimoine #VilleLumière #Documentaire #Histoire #Culture #Architecture
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