Ancient corridors below the French capital have served as its ossuary, playground, brewery, and perhaps soon, air conditioning.
- People have been digging up limestone and gypsum from below Paris since Roman times.
- They left behind a vast network of corridors and galleries, since reused for many purposes — most famously, the Catacombs.
- Soon, the ancient labyrinth may find a new lease of life, providing a sustainable form of air conditioning.
Ancient mining areas below Paris for limestone (red) and gypsum (green).Credit: Émile Gérards (1859–1920) / Public domain
"If you're brave enough to try, you might be able to catch a train from UnLondon to Parisn't, or No York, or Helsunki, or Lost Angeles, or Sans Francisco, or Hong Gone, or Romeless."
China Miéville's fantasy novel Un Lun Dun is set in an eerie mirror version of London. In it, he hints that other cities have similar doubles. On the list that he offhandedly rattles off, Paris stands out. Because the City of Light really does have a twisted sister. Below Paris Overground is Paris Underground, the City of Darkness.
Most people will have heard of the Catacombs of Paris: subterranean charnel houses for the bones of around six million dead Parisians. They are one of the French capital's most famous tourist attractions – and undoubtedly its grisliest.
But they constitute only a small fragment of what the locals themselves call les carrières de Paris ("the mines of Paris"), a collection of tunnels and galleries up to 300 km (185 miles) long, most of which are off-limits to the public, yet eagerly explored by so-called cataphiles.
The Grand Réseau Sud ("Great Southern Network") takes up around 200 km beneath the 5th, 6th, 14th, and 15th arrondissements (administrative districts), all south of the river Seine. Smaller networks run beneath the 12th, 13th, and 16th arrondissements. How did they get there?
Paris stone and plaster of Paris
It all starts with geology. Sediments left behind by ancient seas created large deposits of limestone in the south of the city, mostly south of the Seine; and gypsum in the north, particularly in the hills of Montmartre and Ménilmontant. Highly sought after as building materials, both have been mined since Roman times.
The limestone is also known as Lutetian limestone (Lutetia is the Latin name for ancient Paris) or simply "Paris stone." It has been used for many famous Paris landmarks, including the Louvre and the grand buildings erected during Georges-Eugène Haussmann's large-scale remodelling of the city in the mid-19th century. The stone's warm, yellowish color provides visual unity and a bright elegance to the city.
The fine-powdered gypsum of northern Paris, used for making quick-setting plaster, was so famed for its quality that "plaster of Paris" is still used as a term of distinction. However, as gypsum is very soluble in water, the underground cavities left by its extraction were extremely vulnerable to collapse.
Like living on top of a rotting tooth: subsidence starts far below the surface, but it can destroy your house.Credit : Delavanne Avocats
In previous centuries, a road would occasionally open up to swallow a chariot, or even a whole house would disappear down a sinkhole. In 1778, a catastrophic subsidence in Ménilmontant killed seven. That's why the Montmartre gypsum quarries were dynamited rather than just left as they were. The remaining gypsum caves were to be filled up with concrete.
The official body governing Paris down below is the Inspection Générale des Carrières (IGC), founded in the late 1770s by King Louis XVI. The IGC was tasked with mapping and, where needed, propping up the current and ancient (and sometimes forgotten) mining corridors and galleries hiding beneath Paris.
A delightful hiding place
Also around that time, the dead of Paris were getting in the way of the living. At the end of the 18th century, their final destination consisted of about 200 small cemeteries, scattered throughout the city — all bursting at the seams, so to speak. There was no room to bury the newly dead, and the previously departed were fouling up both the water and air around their respective churchyards.
Something radical had to happen. And it did. From 1785 until 1814, the smaller cemeteries were emptied of their bones, which were transported with full funerary pomp to their final resting place in the ancient limestone quarries at Tombe-Issoire. Three large and modern cemeteries were opened to receive the remains of subsequent generations of Parisians: Montparnasse, Père-Lachaise, and Passy.
The six million dead Parisians in the Catacombs, from all corners of the capital and across many centuries, together form the world's largest necropolis — their now anonymized skulls and bones methodically stacked, occasionally into whimsical patterns. The Catacombs are fashioned into a memorial to the brevity of life. The message above the entrance reads: Arrête! C'est ici l'empire de la Mort. ("Halt! This is the empire of Death.")
That has not stopped the Catacombs, accessible via a side door to a classicist building on the Avenue du Colonel Henri Rol-Tanguy, making just about every Top 20 list of things to see in Paris.
An underground economy
However, while the Catacombs certainly are the most famous part of the centuries-old network beneath Paris, and in non-pandemic times draw thousands of tourists each day, they constitute just 1.7 km (1 mile) of the 300-km (185-mile) tunneling total.
Subterranean Paris wasn't just used for mining and storing dead people. In the 17th century, Carthusian monks converted the ancient quarries under their monastery into distilleries for the green or yellow liqueur that still carries their name, chartreuse.
Because the mines generally keep a constant cool temperature of around 15° C (60° F), they were also ideal for brewing beer, as happened on a large scale from the end of the 17th century until well into the 20th century. Several caves were dug especially for establishing breweries, and not just because of the ambient temperature: going underground allowed brewers to remain close to their customers without having to pay a premium for real estate up top.
Overview of the Paris Catacombs.Credit: Inspection Générale des Carrières, 1857 / Public domain.
At the end of the 19th century, the underground breweries of the 14th arrondissement alone produced more than a million hectoliters (22 million gallons) per year. One of the most famous of Paris' underground breweries, Dumesnil, stayed in operation until the late 1960s.
In that decade, the network of corridors and galleries south of the Seine, long since abandoned by miners, became the unofficial playground for the young people of Paris. They explored the fantastical world beneath their feet, in some cases via entry points located in their very schools. Fascinated, these cataphiles ("catacomb lovers") read up on old books, explored the subterranean labyrinth, and drew up schematics that were passed around among fellow initiates as reverently as treasure maps.
As Robert Macfarlane writes in Underland, Paris-beneath-their-feet became "a place where people might slip into different identities, assume new ways of being and relating, become fluid and wild in ways that are constrained on the surface."
Some larger caves turned into notorious party zones: a 7-meter-tall gallery below the Val-de-Grâce hospital is widely known as "Salle Z." Over the last few decades, various other locations in subterranean Paris have hosted jazz and rock concerts and rave parties — like no other city, Paris really has an "underground music scene."
Hokusai's Great Wave as the backdrop to the "beach" under Paris.Credit: Reddit
Cataphiles vs. cataphobes
With popularity came increased reports of nuisance and crime — the tunnels provided easy access to telephone cables, which were stolen for the resale value of their copper.
The general public's "discovery" of the underground network led the city of Paris to officially interdict all access by non-authorized persons. That decree dates back to 1955, but the "underground police" have an understanding with seasoned cataphiles. Their main targets are so-called tourists, who by their lack of knowledge expose themselves to risk of injuries or worse, and degrade their surroundings, often leaving loads of litter in their wake.
The understanding does not extend to the IGC. Unlike in the 19th century, when weak cavities were shored up by purpose-built pillars, the policy now is to inject concrete to fill up endangered spaces — thus progressively blocking off parts of the network. That procedure has also been used to separate the Catacombs to prevent "infiltration" of the site by cataphiles.
Many subterranean streets have their own names, signs and all. This is the Rue des Bourguignons (Street of the Burgundians) below the Champs des Capucins (Capuchin Field), neither of which exists on the surface.Credit: Jean-François Gornet via Wikimedia and licensed under
The cataphiles, however, are fighting back. In a game of cat and mouse with the authorities, they are reopening blocked passages and creating chatières ("cat flaps") through which they can squeeze into chambers no longer accessible via other underground corridors.
Catacomb climate control
Alone against the unstoppable tide of concrete, the amateurs of Underground Paris would be helpless. But the fight against climate change may turn the subterranean labyrinths from a liability into an asset — and the City of Paris into an ally.
The UN's 2015 Climate Plan — concluded in Paris, by the way — requires the world to reduce greenhouse gas emissions by 75 percent by 2050. And Paris itself wants to be Europe's greenest city by 2030. More sustainable climate control of our living spaces would be a great help toward both targets. A lot of energy is spent heating houses in winter and cooling them in summer.
This is where the constant temperature of the Parisian tunnels comes in. It's not just good for brewing beer; it's a source of geothermal energy, says Fieldwork, an architectural firm based in Paris. It can be used to temper temperatures, helping to cool houses in summer and warming them in winter.
One catch for the cataphiles: it also works when the underground cavities are filled up with concrete. So perhaps one day, Paris Underground, fully filled up with concrete, will completely fall off the map, reducing the city's formerly real doppelgänger into an air conditioning unit.
Cool in summer, warm in winter: Paris Underground could become Paris A/C.Credit: Fieldwork
Strange Maps #1083
Got a strange map? Let me know at firstname.lastname@example.org.
In May 2018, the city of Paris set an ambition to be carbon-neutral by 2050.
- Countries, governments and companies are aligning on a need for net-zero - and this is an opportunity to rethink decarbonizing our cities.
- There is no "one-size-fits-all" solution – each city's needs must be at the heart of developing integrated energy solutions.
- A city can only decarbonize through collaboration between government, the private sector, and local communities.
The world is at a critical juncture. Never has there been a moment where businesses, energy consumers and governments – from Canada to China – are aligning on a common vision like this: a road to net-zero emissions.
In the years ahead the role played by cities will be under greater scrutiny than ever before. Cities are, after all, the beating heart of business, commerce, trade and society. They cover 3% of the earth's land surface yet they are responsible for more than 70% of all carbon emissions. Cities are where the need for integrated energy solutions, backed up by ambitious policy and urban planning, will be critical if the world is to move towards net-zero emissions in the years ahead.
The private sector has a role to play. Over the past few years, companies and industries have begun to ask how they can play their part. Many in the energy sector are on a mission to help customers decarbonize within their own sectors, businesses, communities and homes. But how could that work for cities?
While every city has unique needs, five are common to building sustainable and smarter cities of the future. These are mobility, energy, environment, urban planning and living. And it is a mix of these elements that is required to develop integrated solutions. To better understand the different needs, convening a diverse set of city stakeholders is key. This I would like to describe as co-visioning.
For example, in May 2018 the city of Paris set an ambition to be carbon-neutral by 2050. This ambition is not without challenges. Rising levels of income and wealth inequality, transport emissions and older and energy-inefficient building stock are among the challenges standing in the way of that goal.
In 2019, Shell, alongside Leonard (a foresight and innovation platform) and the Organisation for Economic Co-operation and Development (OECD), hosted a City Scenarios workshop in Paris. This event brought together 45 key stakeholders from across both public and private sectors and the wider community, who discussed how to collectively address and meet the objectives of the Paris Climate Action Plan, which aims to make Paris a carbon-neutral city by 2050.
The outcomes of this workshop led to a sketch that explores three scenarios. Each describes different visions of the future for the Paris Metropole, while illustrating a pathway to 2050 and describes progress, or lack thereof, towards the goals of the Paris Climate Action Plan. A short description of each scenario is described in the visual below.
The purpose of this exploration was to guide the wisest possible choices and actions that should be taken now, to achieve the shared ambitions for the Paris region. Far from being a regular commercial opportunity, this instead looked to envision future scenarios and what customers' needs in the future could look like. This work has enabled us to better integrate solutions in the years ahead.
After understanding the needs, one approach to co-innovate solutions is to adopt a 'Living Lab' concept. In Singapore, we launched a City Solutions Living Lab to co-create and experiment with city stakeholders' innovative concepts, scenarios, technologies and business models in actual living environments.
The island city-state is forward thinking in its approach to energy transition. It has set ambitious targets to increase renewables, and announced that it plans to phase out petrol and diesel vehicles by 2040. With this shared vision, Shell partnered Singapore's Energy Market Authority (EMA) to jointly work on spurring the adoption of energy storage systems to support the deployment of more solar in Singapore. One ongoing project is to work with local enterprises to develop smart energy-management system solutions that integrate solar and storage to provide fast charging for electric vehicles at Shell service stations.
There is no one-size fits all solution. Starting from each city's needs, integrated solutions need to be innovated and delivered. This will require unprecedented collaboration between government, industry and society. But the urgency has never been greater. After all, making cities sustainable places to live and work for future generations will be imperative if the world is to meet the broader goals of the Paris Agreement and move closer to a net-zero emissions world.
The word "learning" opens up space for more people, places, and ideas.
- The terms 'education' and 'learning' are often used interchangeably, but there is a cultural connotation to the former that can be limiting. Education naturally links to schooling, which is only one form of learning.
- Gregg Behr, founder and co-chair of Remake Learning, believes that this small word shift opens up the possibilities in terms of how and where learning can happen. It also becomes a more inclusive practice, welcoming in a larger, more diverse group of thinkers.
- Post-COVID, the way we think about what learning looks like will inevitably change, so it's crucial to adjust and begin building the necessary support systems today.
This video is part of Z 17 Collective's Future of Learning series, which asks education thought leaders what learning can and should look like in the midst and wake of the coronavirus pandemic.
Ground-penetrating radar allows the non-invasive virtual excavation of Falerii Novi.
- Using ground-penetrating radar, layers of an ordinary field in Italy are pulled back to reveal a lost Roman town.
- Without disturbing a single artifact, an incredible level of detail is uncovered.
- The buried town, Falerii Novi, has been quietly awaiting discovery since it was abandoned at the start of medieval age.
It doesn't look like much to the naked eye. It's basically an empty field, but if you caught it on the right days, you'd have seen a quad-wheel bike going back and forth while pulling an unremarkable-looking bit of not-really-farm gear. What's been going on there is the layer-by-layer discovery of an ancient Roman town, Falerii Novi. While archaeological finds like this are always interesting, this one is special: The long-buried city has been exposed without the removal of a speck of dirt.
Technology and patience
Image source:Frank Vermeulen/University of Cambridge
Falerii Novi was unearthed using ground-penetrating radar, or GPR. With each pass across that field, the bike pulled a rolling frame outfitted with a GPR instrument that bounced radio waves off of whatever lay beneath it. The device took a reading every 12.5 centimeters, eventually imaging the entire 30.5-hectare area. Without disturbing a single ancient artifact, GPR generated a remarkably detailed look at the lost city, with its various different layers depicting changes that occurred over time.
In the end, the researchers were confronted with 28 billion GPR data points to be processed, an almost impossibly huge task. Each hectare takes about 20 hours to work through, and the team is currently developing automation techniques that will allow them to fully explore the data collected by the GPR.
"The astonishing level of detail which we have achieved at Falerii Novi, and the surprising features that GPR has revealed, suggest that this type of survey could transform the way archaeologists investigate urban sites, as total entities."
A preliminary version of the Falerii Novi map
Image source: University of Cambridge
Quite a bit was already known about the walled town of Falerii Novi. It was first occupied in 241 BC, and lasted until around 700 AD., the early days of the medieval period. It's located about 30 miles north of Rome. The town, which was about half the size of Pompeii, has been the subject of other scanning research before, but has never been so thoroughly revealed until now.
Image source: L. Verdonck/University of Cambridge
The visible Falerii Novi contains a number of surprises.
In a broad sense, the town's layout appears less standardized than archaeologists would expect for an ancient Roman community, with a number of notable features.
There's the mysterious pair of large structures facing each other within a porticus duplex located at the town's northern gate at the upper edge of the image above. Experts have no idea what these buildings are, though they conjecture that they may have been some sort of massive monument overlooking the city's edge.
In addition, for a small city, the temple, market building and bath complex are unexpectedly elaborate.
GPR also revealed the existence of an intriguing network of pipes that may have been a large public bathing system featuring an open-air natatio, or pool. The pipes terminate at a large rectangular building and run not just along the town's streets, as might be expected, but also under its city blocks.
With the Falerii Novi project serving as such a stunning reason to keep using this technology for archaeology, Millet envisions many more such projects: "It is exciting and now realistic to imagine GPR being used to survey a major city such as Miletus in Turkey, Nicopolis in Greece or Cyrene in Libya. We still have so much to learn about Roman urban life and this technology should open up unprecedented opportunities for decades to come."
Gallup found that in 2019, movie attendance didn't even come close to library visits.
- Of all public cultural destinations, libraries are the most often visited.
- Libraries' expanded offerings make them more attractive than ever, especially to lower-income groups.
- Women are far more likely than men to visit a library.
Amazingly, when it comes to getting up off our butts and engaging in cultural activities out in the world, Americans, by far, most frequently choose to go… to the library. Seriously. Twice as often as movies, more than sports or music, museums, or anything else, according to new research published by Gallup. Though one explanation may be that we often don't have to go out any more to see movies or sports, when it comes to leaving the safety of our domiciles, yes, libraries are our #1 destination.
Not even close
Image source: Tobias Messer/unsplash
The overall average number of trips we made in 2019 to various cultural resources:
- Go to a library — 10.5
- Go to a movie at a movie theater — 5.3
- Attend a live sporting event — 4.7
- Attend a live music or theatrical event — 3.8
- Visit a national or historical park — 3.7
- Visit a museum — 2.5
- Visit a gambling casino — 2.5
- Go to an amusement or theme park — 1.5
- Visit a zoo — 0.9
Image source: Robert Bye/unsplash
Cellular and landline telephone interviews were conducted December 2-15 of last year. There were more cellular respondents than landline, which seem right these days. 1,025 adults were questioned from all 50 U.S. states, and the results have a sampling error margin of ±4%.
This is Gallup's first survey update since 2001, and reveals a 1,3-trip reduction in the number of movies attended, though again, this could simply mean we're choosing to view them more often at home.
Who’s making all these trips to the library?
Image source: Danny/unsplash
Gallup found that women are almost twice as likely to visit la bibliothèque, with 13.4 visits as apposed to men's 7.5. On the other hand, men were more likely to frequent casinos, sporting events, and parks.
Today's libraries offer, of course, more than books, most notably, computers for internet access and WiFi, and so it's not surprising that lower-income respondents paid them a greater number of visits. They're also the group most often visiting casinos.
The people who use libraries the least are those who make more than $100,000 annually. These people, conversely, are the most frequent attendees of events that carry higher ticket prices such as movies, shows, and concerts.
While it's no shock that the age group most likely to visit a library are those of student age, 18-29, the group with the highest overall attendance record for all cultural activities are those from 30-49. Their average, 7.4, is more than three points higher than older adults and more than twice the number of visits for younger adults. Gallup suggests this may reflect a time of life when one is still relatively young but is more likely to have the money to pay for entertainments.
Gallup found certain clear regional preferences among the cultural destinations they tracked. Residents of the eastern U.S. are the most frequent museum-goers, while those in the West, more often visit parks and casinos.
Exceptional U.S. libraries
Image source: Checubus/Shutterstock
Gallup's not the only organization with an interest in library attendance, and Literary Hub has identified the 12 most popular libraries globally, three of which are in the U.S.:
- New York Public Library, New York, NY — 18 million visitors annually
- Brooklyn Public Library, Brooklyn, NY — 8.1 million visitors annually
- Library of Congress, Washington D.C. — 1.9 million visitors annually
The American Library Association publishes a list of the 25 biggest U.S. libraries, and some of these places are jaw-droppingly gorgeous, as demonstrated by Curbed's list of the 20 most beautiful American libraries. Huffington Post tells you where to find the best library in each state.
The national library picture
Image source: American Libraries Magazine's April 2019 Special Report
Libraries' ever-expanding offerings have likewise expanded their importance as community centers in addition to being a place from which to borrow books. American Libraries Magazine's April 2019 Special Report concludes that library attendance is on the rise. 2016 saw 1.4 billion visits to public libraries, which works out to 4 million visits a day and roughly 2,664 visits per minute. There are more public libraries (16,568) than Starbucks (14,606).
In line with Gallup's findings that libraries are of particular importance to people with lower incomes, some of the largest U.S. libraries are abandoning fees for overdue books to ensure that they're not penalizing — or worse, turning away — the people who most depend on free books and the other services libraries supply.
Though ample data supports the benefits public libraries provide to communities, the rise of anti-science, anti-education, and anti-diversity attitudes are posing new challenges for libraries, ranging from conflicts over acceptable content to budgeting. The Trump administration, for example, has advocated the last three years running that Federal funding of public libraries be eliminated . Fortunately, the proposal faced sufficient opposition that funding was increased in the final legislation. Funding for public libraries on the state and local levels continues to be often insecure even as libraries continue to assume their place as brick-and-mortar community centers for the modern world.