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“Wonderfully unimpressive”: hill-climbing in London
For urban exploration with an ironic twist, go 'bag' all 32 London Borough Tops
London is an unlikely destination for hill-climbing. The local topography is mostly flat, with some soft undulations. The city’s tallest building – the Shard, at 306 m (1,000 ft) or 310 m (1,020 ft) if you include the tip – easily beats the highest natural point, Westerham Heights in the south-eastern borough of Bromley (245 m, 804 ft).
But if you’re in London anyway and you’ve seen all of the usual sights, why not seek out the highest points in each of its 32 boroughs? Yes, many are ridiculously low and obscure. Nevertheless, ‘hill bagging’ is a thing even in London, as an alternative and mildly ironic (and thus perhaps very British) form of urban exploration. Alternatively, there's the London Peaks Relay, a 240-km (150-mile) race in which a team of runners visit the highest point in every London borough within 24 hours.
Here’s an overview of the 32 tumps (1) you have to 'climb' before you can consider yourself the conqueror of London's Borough Tops. While none is a challenge individually, together they add up to 2,996 m (9,829 ft) – more than twice the height of Britain's highest mountain, the redoubtable Ben Nevis, at 1,344 m (4,409 ft).
1. Westerham Heights, Bromley: 245 m (804 ft)
The 2,141st-highest peak in England and the 13,201st-highest peak in the British Isles.
- “Traffic on the A233 is lethal and the top is on a blind corner”.
- “Maybe we could petition the house owner to get a huge granite slab installed in the garden as a summit feature.”
- “Got as close as I could without upsetting people or horses!”
Westerham Heights is a separately named part of Betsom’s Hill, which peaks just across the county border in Kent. It’s both the highest point of the North Downs and of Kent. Its ranking as the 2,141st-highest peak in England (and the 13,201st-highest in the British Isles) derives from the Database of British and Irish Hills (DoBIH), as quoted by The Mountain Guide, from which the other rankings – where available – were also taken. The quotes are from climbers who have bagged the ‘hills’ in question, taken from the Hill Bagging website.
2. Sanderstead Plantation, Croydon: 175 m (574 ft)
The 3,045th-highest peak in England and the 15,722nd-highest peak in the British Isles.
- “The little hillock is clearly marked with information in a plastic wallet”.
- “Nice woods, but the brambles on the top are getting a bit long. Not one for shorts”.
- “Pleasant spot. Clearing with 2 small benches and a large tree in the middle”.
3. Bushey Heath, Harrow: 153 m (502 ft)
The 3,361st-highest peak in England and the 16,538th-highest peak in the British Isles. Also formerly the summit of Hertfordshire.
- “Nice boundary stone opposite sude of the road from the Harvester”.
- “Easy one, this: park in the Harvester car park, get a coffee and then before you drive off, hop over the road and bag yourself a county top”.
- “These sort of tump summits on totally flat urban roads are such a pointless nonsense aren't they!”
4. Clock House, Sutton: 147 m (482 ft)
The 3,437th-tallest in England and the 16,776th-highest peak in the British Isles.
- “Top in the corner of playing field just over the stile”.
- “Popular dog walking spot, nice high hill but no views to speak of”.
- “Glad people weren't playing football here or it could have been embarrassing”.
5. Highwood Hill, Barnet: 146 m (479 ft)
The 3,453rd-highest peak in England and the 16,811th-highest peak in the British Isles.
- “Access nightmare. Watch out for electric fences and angry horses”.
- “Asked to proceed to top on private land – denied”.
- “In the dark over fence from east into grassy field and up to paddock summit. Kept torch off”.
6. Potter Street Hill, Hillingdon: 134 m (440 ft)
The 3,595th-highest peak in England, and the 17,224th-highest peak in the British Isles.
- “Some very posh property”.
- “Short amble through Oxhey Wood from the car park”.
- “A pleasant mile uphill from Northwood Hills station. The presence of the City of London Coal Duty post near the top was an added bonus”.
7. Spaniards Road, Camden: 134 m (440 ft)
Also mentioned as Hampstead Heath. The high point is at or near where these two meet.
- “Saw several of the resident bright green parakeets”.
- “I agree on the difficulty in finding the natural top. It may be in the large building being restored next to the memorial. The gate was open, so I wandered in. Good views of London through the trees near the summit”.
- “No real top, just a bus stop and hundreds of other Sunday walkers for company”.
8. Eaglesfield Recreation Ground (part of Shooters Hill), Greenwich: 132 m (433 ft)
- “Also visited nearby Severndroog castle”.
- “Walked up from Falconwood railway station through Oxleas Wood and Oxleas Meadows - much nicer approach than most London Tumps!”
- “Nice parkland, Great views SE, interesting architecture tower”.
9. Highgate, Haringey: 129 m (423 ft)
The 3,661st-highest peak in England, and the 17,420th-highest peak in the British Isles.
- “Only room for one of us at a time on this tiny roundabout!”
- “Rather inauspicious”.
- “Not recommended at rush hour”.
10. Bournwell Hill, Enfield: 119 m (390 ft)
The 3,762nd-highest peak in England, and the 17,758th-highest peak in the British Isles.
- “Walk down hill to the top. Near gate. nearby lamp-post proclaims highest point in Enfield”.
- “Nice leafy stroll from Cockfosters tube to the top - lunch beside cricket pitch”.
- “Unremarkable. Note to self not to return”.
11. Sydenham Hill, Southwark/Lewisham: 112 m (367 ft)
The 3,857th-highest peak in England, and the 18,024th-highest peak in the British Isles.
- “Following a visit to the Horniman Museum & Gardens, a pleasant walk up leafy Sydenham Hill”.
- “Nice pub nearby!”
- “Could be anywhere”.
12. Westow Hill, Lambeth: 110 m (361 ft)
The 3,885th-highest peak in England, and the 18,103rd-highest peak in the British Isles.
- “Busy and dangerous road top, shame the highest point not in the nearby Crystal Palace Park”.
- “By black-painted pub at unpleasantly busy road junction”.
- “I walked around the roundabout via the crossings, then seized my chance to carefully walk across the centre during a momentary lull in traffic”.
13. Havering-atte-Bower, Havering: 105 m (344 ft)
The 3,941st-highest peak in England, and the 18,306th-highest peak in the British Isles.
- “Highest point appears to be churchyard near SE corner”.
- “Great village sign and unusual arch and main entrance under church tower”.
- “Nice view of east London from here”.
14. Dartmouth Park Hill, Islington: 100 m (328 ft)
(near Highgate Hill, also mentioned as the borough high point, with the same altitude)
- “The high point appears to be at the boundary stones/mile posts”.
- “Excellent selection of real ales at the nearby Duke’s Head”.
- “Alongside is Highgate Cemetery (…) Notable for being a nature reserve (lots of foxes) and for some of the people buried there such as Karl Marx (…), but also Douglas Adams who I like to think would have described Marvin plodding around bagging London Borough Tops moaning that ‘the first 32 were the worst’…”
15. Sudbury, Brent: 91 m (299 ft)
The 4,084th-highest peak in England, and the 18,805th-highest peak in the British Isles.
- “A glorious sunny winter day and a good little hill to mark 71st birthday!”
- “A surprisingly pleasant hill in a pleasant neighbourhood”.
- “The views over north London were spectacular”.
16. Pole Hill, Waltham Forest: 91 m (299 ft)
The 4,085th-highest peak in England, and the 18,806th-highest peak in the British Isles.
- “Short walk, good view, trig point an obelisk, marking meridian line and a plaque about TE Lawrence. Proper hill unlike other London ones I have done”.
- “Easy walk from Chingford station. Nice top in woods with view to Shard”.
- “Definitely one of the better London Borough Tops”.
17. Cabin Hill, Redbridge: 90 m (295 ft)
- “Parked in the car park to the north then wandered about the flattish summit. A pleasant spot”.
- “Popular recreation area with golf course approach from Havering”.
- “Very nice spot - probably my favourite of all the borough tops”.
18. Telegraph Hill, Kingston upon Thames: 90 m (295 ft)
- “Parked at pub, then up track to clay pigeon shooting ground. Nobody blasting away & spoke to two nice guys who let me cross the ground to the reservoir compound”.
- “Did not try to climb locked gate at road due to warning signs, and tales of an impenetrable inner fenced compound and security cameras”.
- “Fenced off as described by others so settled for highest point outside the fence. Shame it can't be claimed”.
19. Horsenden Hill, Ealing: 85 m (279 ft)
The 4,149th-highest peak in England, and the 19,035th-highest peak in the British Isles.
- “A proper hill with good views and paths”.
- “A conservation area of woodland and rough grass. Archaeological evidence has shown that people occupied the site for at least 7000 years. The ancient plough soil on the hill top suggests Neolithic farming. The Ballet Box Public House is so called because of its use as a polling station for canal boatmen”.
- “Not a bad top apart from the shady characters in the car park”.
20. Langdon Shaw, Bexley: 83 m (272 ft)
The 4,161st-highest peak in England, and the 19,099th-highest peak in the British Isles.
- “Driveway of house tucked into corner (left of the fancy, out-of-place gates) seems to be summit although there could be a back garden a few cm higher”.
- “Two days ago, I was walking in the mountains around Lake Como: the contrast (is) surreal”.
21. Putney Heath, Wandsworth: 60 m (197 ft)
- “Big lump of a hillock in the middle of the heath”.
- “Wonderfully unimpressive”.
- “I returned to the Windmill Cafe with burdock seed-heads all over my rucksack”.
22. Richmond Park, Richmond upon Thames: 56 m (184 ft)
The 4,337th-highest peak in England, and the 19,888th-highest peak in the British Isles.
- “Who thought London could be so lovely?”
- “A deer stepped out of the margins of the wood quite close to me in the twilight. Admired the view from King Henry's mound and toured the potential high points. Either the grassy road verge or the ground by a tree 50 yards North West of the trig, near the fence, for my money”.
- “I'm glad I live in Scotland. These English hills are just so difficult. Finding the exact top is like being blindfolded and trying to stick the tail on a donkey in a spin dryer”.
23. Lauriston Road, Merton: 55 m (180 ft)
The 4,343rd-highest peak in England, and the 19,925th-highest peak in the British Isles.
- “Wandered over from an afternoon drinking in the Crooked Billet - fine pub, dull hill”.
- “A blue plaque at the road end marks a house where the WWI war poet Robert Graves lived”.
- “Very flat area, posh but not scenic for a top. Highest lump on road marked, maybe appropriately, with a pile of horse dung today”.
24. Boundary Road, Westminster: 52 m (170 ft)
Also mentioned as St John's Wood Park Road. The high point is at or near the junction of these two roads.
- “Reckon the actual top is the base of the Plane tree or perhaps even the junction of Boundary Rd and The Marlowes. Took in the Abbey Rd zebra crossing for good measure”.
- “Seems to be at end of the block paved drive to me. It's all debatable as both pavement and block-paved drive are man-made”.
- “I had the impression that I was walking downhill from Swiss Cottage for this one”.
25. College Park, Hammersmith and Fulham: 45 m (148 ft)
The 4,397th-highest peak in England, and the 20,191st-highest peak in the British Isles.
- “The high point is by Travis Perkins it would appear. I liked the house just down the road called 'Belle Vue'. Maybe once upon a time!”
- “Combined with the adjacent Harrow Road top outside the intriguing Kensal Green Cemetery which is well worth exploring for its history and wide range of different grave styles from different faiths”.
- “A short walk from Kensal Green station. Seems to be the Portuguese/Brazilian quarter around here”.
26. Harrow Road, Kensington and Chelsea: 45 m (148 ft)
The 4,398th-highest peak in England, and the 20,192nd-highest peak in the British Isles.
- “An engraved stone on the wall of 691C appears to show a boundary line. Otherwise, the topographical excitement around here is limited”.
- “Really not worth the time and effort in getting here”.
- “Bagged on way back from board meeting. Rubbish but slightly better than the one up the road”.
27. Marks Gate, Barking and Dagenham: 43 m (141 ft)
- “Easy approach as downhill from Havering Atte Bower church”.
- “Easy parking in nearby Billet Road, which about the only good thing I can say about this top. A boring and busy main road. The nearby McDonalds is named after the top - is London Borough Top bagging really getting that popular?!”
- “Highest spot in the new part of the cemetery or across road in quarry site”.
28. Seven Sisters Road, Hackney: 39 m (128 ft)
The 4,429th-highest peak in England, and the 20,358th-highest peak in the British Isles.
- “Yippee, yet another road junction! At least it was only a short stroll from the tube”.
- “Rather dull”.
- “Pleasant park nearby”.
29. The Vale, Hounslow: 35 m (115 ft)
- “The high point appears to be in an industrial estate at 34 metres, although it's all flat there too so near impossible to pick the highest point”.
- “Every day at Heathrow 1,400 flights take off and land – one every 45 seconds which is nearly half a million per year and all of them fly low over here as the end of the runway is only 2 miles away and points this way”.
- “I think this need to be validated - Hard to believe this is a top of anything”.
30. Beckton Alps, Newham: 35 m (115 ft)
- “From Beckton DLR station via zig zag path and gap in fence. Great views over London!”
- “Popular spot judging by the amount of litter on top, which is not surprising given the fantastic 360-degree views”.
- “A wonderful sense of dereliction”.
31. Swanfield Street, Tower Hamlets: 18 m (59 ft)
- “Highest point is the bandstand in the small circular park”.
- “Beaten to be first to log this hill by my daughter and then only by 10 minutes”.
- “A quick detour on a sunny evening, bound for City airport”.
London has 32 boroughs, but the map (and this list) has only 31 tops. That’s because Sydenham Hill, on the border between Southwark and Lewisham, is the highest point in both boroughs. Not mentioned on the map is the highest point in the City of London, which is a separate and independent entity, not part of Greater London as such.
Chancery Lane/Holborn, City of London: 22 m (72 ft)
- “Cheating really. I was on a 25 bus”.
- “Climbed up the steps in Holborn Station from the lowest platform just to get a sense of altitude gain. Oxygen tanks and crampons not needed”.
- “I'd walked across this pavement summit several times whilst working in London, without realising it was a high point. How strange to revisit it now in a stolen moment of a day trip from Scotland to London for work”.
Strange Maps #906
Got a strange map? Let me know at firstname.lastname@example.org.
(1) In England, a hillock, mound, barrow or tumulus. May be related to the Welsh twmp.
"Deepfakes" and "cheap fakes" are becoming strikingly convincing — even ones generated on freely available apps.
- A writer named Magdalene Visaggio recently used FaceApp and Airbrush to generate convincing portraits of early U.S. presidents.
- "Deepfake" technology has improved drastically in recent years, and some countries are already experiencing how it can weaponized for political purposes.
- It's currently unknown whether it'll be possible to develop technology that can quickly and accurately determine whether a given video is real or fake.
After former U.S. President William Henry Harrison delivered his inaugural speech on March 4, 1841, he posed for a daguerreotype, the first widely available photographic technology. It became the first photo taken of a sitting American president.
As for the eight presidents before Harrison, history can see them only through artistic renderings. (The exception is a handful of surviving daguerreotypes of John Quincy Adams, taken after he left office. In his diary, Adams described them as "hideous" and "too true to the original.")
But a recent project offers a glimpse of what early presidents might've looked like if photographed through modern cameras. Using FaceApp and Airbrush, Magdalene Visaggio, author of books such as "Eternity Girl" and "Kim & Kim," generated a collection of convincing portraits of the nation's first presidents, from George Washington to Ulysses S. Grant.
Modern Presidents George Washington https://t.co/CURJQB0kap— Magdalene Visaggio (@Magdalene Visaggio)1611952243.0
What might be surprising is that Visaggio was able to generate the images without a background in graphic design, using freely available tools. She wrote on Twitter:
"A lot of people think I'm a digital artist or whatever, so let me clarify how I work. Everything you see here is done in Faceapp+Airbrush on my phone. On the outside, each takes between 15-30 mins. Washington was a pretty simple one-and-done replacement."
Ulysses S Grant https://t.co/L1IGXLI3Vl— Magdalene Visaggio (@Magdalene Visaggio)1611959480.0
"Other than that? I am not a visual artist in any sense, just a hobbyist using AI tools see what she can make. I'm actually a professional comics writer."
Did another pass at Lincoln. https://t.co/PdT4QVpMbn— Magdalene Visaggio (@Magdalene Visaggio)1611973947.0
Of course, Visaggio isn't the first person to create deepfakes (or "cheap fakes") of politicians.
In 2017, many people got their first glimpse of the technology through a video depicting former President Barack Obama warning: "We're entering an era in which our enemies can make it look like anyone is saying anything at any point in time." The video quickly reveals itself to be fake, with comedian Jordan Peele speaking for the computer-generated Obama.
While deepfakes haven't yet caused significant chaos in the U.S., incidents in other nations may offer clues of what's to come.
The future of deepfakes
In 2018, Gabon's president Ali Bongo had been out of the country for months receiving medical treatment. After Bongo hadn't been seen in public for months, rumors began swirling about his condition. Some suggested Bongo might even be dead. In response, Bongo's administration released a video that seemed to show the president addressing the nation.
But the video is strange, appearing choppy and blurry in parts. After political opponents declared the video to be a deepfake, Gabon's military attempted an unsuccessful coup. What's striking about the story is that, to this day, experts in the field of deepfakes can't conclusively verify whether the video was real.
The uncertainty and confusion generated by deepfakes poses a "global problem," according to a 2020 report from The Brookings Institution. In 2018, the U.S. Department of Defense released some of the first tools able to successfully detect deepfake videos. The problem, however, is that deepfake technology keeps improving, meaning forensic approaches may forever be one step behind the most sophisticated forms of deepfakes.
As the 2020 report noted, even if the private sector or governments create technology to identify deepfakes, they will:
"...operate more slowly than the generation of these fakes, allowing false representations to dominate the media landscape for days or even weeks. "A lie can go halfway around the world before the truth can get its shoes on," warns David Doermann, the director of the Artificial Intelligence Institute at the University of Buffalo. And if defensive methods yield results short of certainty, as many will, technology companies will be hesitant to label the likely misrepresentations as fakes."
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 email@example.com.
Meconium contains a wealth of information.
- A new study finds that the contents of an infants' first stool, known as meconium, can predict if they'll develop allergies with a high degree of accuracy.
- A metabolically diverse meconium, which indicates the initial food source for the gut microbiota, is associated with fewer allergies.
- The research hints at possible early interventions to prevent or treat allergies just after birth.
The prevalence of allergies arising in childhood has increased over the last 50 years, with 30 percent of the human population now having some kind of atopic disease such as eczema, food allergies, or asthma. The cause of this increase is still subject to debate, though it has been associated with a number of factors, including changes to the gut microbiomes of infants.
A new study by Canadian researchers published in Cell Reports Medicine may shed further light on how these allergies develop in children by examining the contents of their first diaper.
The things you do for science
The research team examined the first stool of 100 infants from the CHILD Cohort Study. The first stool of an infant is a thick, green, horrid-looking substance called meconium. It consists of various things that the infant ingests during the second half of gestation. Additionally, it provides not only a snapshot of what the infant was exposed to during that time, but it also reveals what the food sources will be for the initial gut bacteria that colonize the baby's digestive tract.
The content of the meconium was examined and found to contain such varied elements as amino acids, lipids, carbohydrates, and myriad other substances.
A graph of the comparative, summed abundance of different elements in a metabolic pathway after scaling to median abundance of each metabolite. The blue figures are those children without atopy, the yellow ones show the data for those with an atopic condition. Petersen et al.
The authors fed this information into an algorithm that used this data, along with the identities of the bacteria present as well as the baby's overall health, to predict which infants would go on to develop allergies within one year. The algorithm got it right 76 percent of the time.
A way to prevent childhood allergies?
Infants whose meconium had a less diverse metabolic niche the initial microbes to settle in the gut were at the highest risk of developing allergies a year later. Many of these elements were associated with the presence or absence of different bacterial groups in the digestive system of the child, which play an increasingly appreciated role in our overall health and development. The findings were summarized by senior co-author Dr. Brett Finlay:
"Our analysis revealed that newborns who developed allergic sensitization by one year of age had significantly less 'rich' meconium at birth, compared to those who didn't develop allergic sensitization."
The findings could be used to help understand how allergies form and even how to prevent them. Co-author Dr. Stuart Turvey commented on this possibility:
"We know that children with allergies are at the highest risk of also developing asthma. Now we have an opportunity to identify at-risk infants who could benefit from early interventions before they even begin to show signs and symptoms of allergies or asthma later in life."
A model for early childhood allergies
Petersen et al.
As shown above, the authors constructed a model of how they believe metabolites and bacterial diversity help prevent allergies. Increased diversity of metabolic products in the meconium encourage the development of "healthy" families of bacteria, like Peptostreptococcaceae, which in turn promote the development of a healthy and diverse gut microbiome. Ultimately, such diversity decreases the likelihood that a child will develop allergies.