Caves – BLDGBLOG

Star Forts, Mines, and Other Maastricht Subterranea

I was in Maastricht, Netherlands, for a couple nights last week, mostly as a way to break-up my trip across the Atlantic and thus help get over jet-lag before attending an archaeology conference (where I currently type this).

I went specifically to Maastricht, however, because it’s home to an astonishing number of subterranean sites, from 800-year-old limestone mines and 17th-century star fortifications to NATO defense bunkers. I basically checked into my hotel then disappeared underground for the rest of the visit.

Here are some pics.

My morning started here, at the entrance to the Casemates Waldeck, a labyrinth of defensive earthworks complete with tunnels, counter-mine tunnels, barracks, and firing positions. Large parts of the system were then later repurposed as civilian air-raid shelters during WWII.

The geometric logic of the forts was—among other things—to lure enemy attackers in over cliff-like artificial drops and ridges, thinking they were on their way to the heart of the city. However, this simply trapped them between huge brick walls, directly in front of disguised gun emplacements, many of which were deliberately aimed at stomach-height to maximize suffering.

If you go through the door seen in the above photographs, meanwhile, you end up inside a bewildering system of multi-level tunnels weaving around for kilometers beneath the outer edge of the city.

Because the city has expanded and grown over the centuries, whole neighborhoods now sit atop these structures; if you live in Maastricht, you might very well have disused military fortification tunnels running under your basement.

What’s more, not all of the tunnels are mapped—which means that some are neither maintained nor stabilized. Apparently, seasonal floods have led to sinkholes above, as streets partially collapse into the system.

And that’s just one of many, many underground sites you can tour.

The next place I headed was called the Zonneberg Caves—which are not natural caves, but a colossal limestone mine—and I honestly can say I would spend entire weeks down there.

I’m just randomly typing facts from memory, because I’m on a break from a conference and want to get these photos up, which means I will almost certainly get a few details wrong, but I believe they said that “only” 80 or so kilometers of these ancient limestone mines remain from more than 200, and that the first shafts were cut in the 13th century.

The mines extend all the way over the international border into Belgium. The Belgian tunnels are apparently closed to the public, yet people sneak into them all the time.

There are 20th-century artworks painted on the walls, much older graffiti etched directly into rock, and massive corridors extending off on all sides into darkness.

If you’re into the underground and ever have an opportunity to spend more time than a tour down there, I would recommend it without any hesitation—and I will be deeply, deeply jealous.

The site is even complete with a little church altar.

Bear in mind, this is all still the same day.

The next site I went to was accessed through a locked metal door in the rock (pictured above). This system, known as the North Caves, is actually physically connected to the Zonneberg Caves, although it would take an hour or more to get between them underground. Like I say, I would go back there and wander around in a heartbeat.

The added interest of this latter system is that parts of it were used during WWII to house paintings by the Old Masters, protecting them from Nazi plunder and stray Allied bombs alike.

At the end, you go into a place called “the Vault” to see where Rembrandts and other paintings were hung while war waged above.

Finally, after many hours underground, I walked outside—and the first thing I saw was this rainbow. A cheesily enjoyable end to a fantastic day.

If you’re tempted to see any of these places yourself, and you hope to do so legally, check out Maastricht Underground for potential tours.

[All photos by Geoff Manaugh/BLDGBLOG.]

Institute for Controlled Speleogenesis

Recently, I’ve been looking back at a collaborative project with John Becker of WROT Studio.

The “Institute for Controlled Speleogenesis” (2014) was a fictional design project we originally set in the vast limestone province of Australia’s Nullarbor Plain.

[Image: A rock-acid drip-irrigation hub for the “Institute for Controlled Speleogenesis,” a collaboration between BLDGBLOG and WROT Studio; all images in this post are by John Becker of WROT Studio.]

The Nullarbor Plain is a nearly treeless region, roughly the size of Nebraska. It is also the world’s largest karst landscape, and thus home to hundreds of natural caves.

“There is a great variety of cave types under the Nullarbor,” as Australian Geographic explains, “but the plain’s most interesting features are long, deep systems (such the Old Homestead Cave), which are found only here, in the U.S. state of Florida, and on Mexico’s Yucatan Peninsula, all of which all have similar karst limestone layers.”

The Institute for Controlled Speleogenesis was imagined as a remote, thinly staffed site for applied geological research, where huge artificial caves could be generated below the Earth’s surface using a special acid mix—as safe as vinegar, but, importantly for our project, capable of dissolving limestone on a greatly accelerated timescale.

Subterranean spaces of every conceivable size, from tiny hollows and capillaries to vast megastructures, could thus be acid-etched into even the deepest karst formations, both rapidly and over decadal expanses of time.

The resulting rooms, tunnels, and interconnected cave systems could be used for a wide range of purposes: generating speleo-pharmaceuticals, for example, as well as testing recreational caving equipment, experimenting with underground agricultural systems, or developing new technologies for subterranean navigation, communication, inhabitation, and mapping.

As John writes on his own website—where you can also see larger, more-detailed versions of these images—our “aberrant caverns,” in John’s phrase, would be monitored in real-time by autonomous systems operating 24 hours a day.

The ever-growing caves could thus be left on their own, unsupervised, while the acid-drip system gradually etches down, drop by drop, reaching increasingly remote underground realms that the acid itself creates.

As a preliminary step, different blends of rock-acid mix would first be tested on large pillars aboveground, to choose or highlight specific spatial effects.

Controlled showers of rock-acid would result in totem-like sculptures, like industrial-scale menhirs—Stone Age ritual artifacts by way of 21st-century geochemistry.

Once the desired effects have been achieved, fields of bladders, nozzles, and injection arrays can be programmed and choreographed to enlarge an artificial cave mouth.

The irrigation system can then be continued underground. Necklaces of acid-drip arrays can easily be extended underground in order to expand the cave itself, but also to lengthen certain tunnels or to experiment with architecturally stable cave formations.

As John explains, the images seen here depict an “injection array using a pressurized system to move large quantities of solution to underlying areas of the cave network. These injection sites are outwardly the tell for a hidden world below. Much like oil derricks extracting resources from the earth, their density and scale across the landscape give you a glimpse into areas afforded the most resources for injection.”

Our initial siting of this in the Nullarbor Plain was motivated entirely by geology, but other large limestone provinces—from Kentucky or northern Arizona to southern France, and from California’s Lucerne Valley to Egypt—would also be good hosts.

While we looked into standard mining acids, currently used for stripping tailings piles of valuable minerals, it quickly became apparent that specific kinds of acetic acid—again, no more toxic than vinegar—offered a more viable approach for creating a maximally spacious site with minimally polluting environmental implications. (Of course, should someone without such qualms want to explore this set-up with no concern for its ecological impact, then much stronger acids capable of dissolving much stronger rocks could also be explored.)

In 2022, I was excited to see that John returned to this project, generating a new series of images using AI image-generation software trained on our earlier project documentation. Given their provenance, the resulting images are unsurprisingly cinematic—equal parts cyberpunk dereliction and underworldly luminescence.

Over the years, John has become a wizard at producing Modernist geological imagery, publishing images on his Instagram account—rock sculpted as smooth as paper and as diaphanous as a veil or curtain.

Check out his own website for more images of the Institute for Controlled Speleogenesis and other recent projects. And, if you like this, don’t miss “Architecture-by-Bee and Other Animal Printheads,” an earlier project of ours that I’m proud to say was published in Paul Dobraszczyk’s excellent recent book, Animal Architecture: Beasts, Buildings and Us.

(All images in this post are by John Becker of WROT Studio. This post contains a Bookshop.org affiliate link, meaning that I might receive a small percentage of any resulting sales.)

The Deep

[Image: Binnewater Kilns, photo by BLDGBLOG.]

While I was over in New York State last fall, reporting both the “witch houses” piece for The New Yorker and the Middletown High School piece for The Guardian, I stopped off in the town of Rosendale, enticed there by several things I noticed on Google Maps.

[Image: The Rosendale Trestle, photo by BLDGBLOG.]

First was what turned out to be a satirical reference to something called the Geo Refrigeration Crevice, which, even on its own, sounded worth a side-trip. But, in the exact same area, there were also photos of an incredible-looking railway bridge converted to a hiking path that I wanted to walk across; there were these gorgeous, ruined kilns built into the hillside; and there were supposedly huge caves.

How on Earth could I drive past all that without stopping?

[Image: Caves everywhere! Photos by BLDGBLOG.]

Being—perhaps to my Instagram followers’ frustration—an avid hiker, I spent far more time there than I should have, mostly looking down into jagged crevasses that extended past the roots of trees, carpeted in fallen leaves, often hidden beneath great, shipwrecked jumbles of boulders slick with the waters of temporary streams.

I crossed the bridge and was ready to hit the road again, when I saw another site of interest on the map. I decided to walk all the way down and around to something called the Widow Jane Mine.

Having visited many mines in my life, I was expecting something like a small arched hole in the side of a hill, probably guarded with a locked gate. Instead, hiking into the woods past some sort of private home/closed mining museum, the ground still damp from rain, I found myself stunned by the unexpected appearance of these huge, moaning, jaw-like holes blasted into the Earth.

[Image: An entrance to the Widow Jane Mine; photo by BLDGBLOG.]

I walked inside and immediately saw the space was huge: a massive artificial cavern extending far back into the hillside. Excuse my terribly lit iPhone photos here, but these images should give you at least a cursory sense of the mine’s scale.

[Image: Inside the Widow Jane Mine; photos by BLDGBLOG.]

Several things gradually became clear as my eyes adjusted to the darkness.

One, I was totally alone in there and had no artificial illumination beyond my phone, whose light was useless. Two, a great deal of the mine was flooded, meaning that the true extent of its subterranean workings was impossible to gauge; I began fantasizing about returning someday with a canoe and seeing how far back it all really goes.

[Image: Flooding inside the Widow Jane Mine; photo by BLDGBLOG.]

Three, there were plastic lawn chairs everywhere. And they were facing the water.

While the actual explanation for this would later turn out to be both entirely sensible and somewhat anticlimactic—the mine, it turns out, is occasionally used as a performance venue for unusual concerts and events—it was impossible not to fall into a more Lovecraftian fantasy, of people coming here to sit together in the darkness, waiting patiently for something to emerge from the smooth black waters of a flooded mine, perhaps something they themselves have invited to the surface…

[Image: Lawn chairs facing the black waters of a flooded mine; photo by BLDGBLOG.]

In any case, at that point I couldn’t be stopped. While trying to figure out where in the world I had left my rental car, I noticed something else in Google’s satellite view of the area—some sort of abandoned factory complex in the woods—so I headed out to find it.

On the way there, still totally alone and not hiking past a single other person, there was some sort of Blair Witch house set back in the trees, collapsing under vegetation and water damage, with black yawning windows and graffiti everywhere. I believe it is this structure in the satellite pic.

[Image: A creepy, ruined house in the woods, photo by BLDGBLOG.]

Onward I continued, walking till I made it, finally, to this sprawling cement plant facility of some sort just standing there in a clearing.

[Image: Cement world; photos by BLDGBLOG.]

I wandered into the silos, looking at other people’s graffiti…

[Image: “Born to Die”—it’s hard to argue with that, although when I texted this photo to a friend he thought it said “Born to Pie,” which I suppose is even better. Photo by BLDGBLOG.]

…before continuing on again to find my car.

Then, though, one more crazy thing popped up, sort of hidden behind those kilns in the opening photo of this post.

There was a door in the middle of the forest! With a surveillance camera!

[Image: Photos by BLDGBLOG.]

It turns out this door leads down into the massive document-storage caverns of Iron Mountain located nearby, a company whose subterranean archive fever was documented in The New Yorker several years ago (albeit referring to a slightly different location of the firm). I would guess that this is the approximate location of that door.

This was confirmed for me by a man sitting alone in a public works truck back at the Binnewater Kilns parking lot, near my rental car. He was smoking a cigar and listening to the radio with his window rolled down when I walked up to the side of his truck and said, “Hey, man, what’s that door in the woods?”

Secret British Caving Teams and the Mineralogy of Nuclear War

[Image: An otherwise unrelated photo of a cave in China, taken by @PhailMachine, via wallhere].

An interesting story that re-emerged during recent coverage of the Thai cave rescue is that a team of British cavers trapped underground in central Mexico for “more than a week” back in 2004 had been accused of having an ulterior motive.

Of the six men, five were British soldiers, and the crew was rescued not by local emergency crews but by a team flown in from Britain. Nothing about either alleged fact is even remotely suspicious, of course, but, according to local press at the time, “the men had been looking for materials that could be used to make nuclear weapons.”

This was apparently more than just a bar-room rumor: Mexico’s energy minister “waded into the row by saying he would send members of the country’s nuclear research institute into the caves because of rumours the British potholers were looking for uranium deposits.” Things “descended into farce,” according to the Guardian, “amid claims the MoD-sponsored expedition was a secret uranium prospecting exercise and that precise details of the trip were not forwarded to the relevant authorities.”

The conspiracy seems to have begun when someone noticed a particular piece of equipment in a photo of the caving team: “someone spotted radon dosimeters being used. This wasn’t a military training exercise; it was a bunch of guys on holiday, some of whom happened to be in the armed services.”

What the British team would even have done with such materials, if they had found them, including how they would have safely transported uranium out of the underworld in their caving gear—not to mention how they would have exploited this knowledge later, perhaps by developing a vast, illegal, underground mine in the middle of central Mexico?—is difficult to imagine, but, wow, would I like to read that novella.

Six British soldiers descend into the Earth beneath Mexico looking for the infernal materials of war, part of a much larger, secret global mission for subterranean weapons-prospecting, slipping into caves in Central America, the U.S. Southwest, the Namibian desert, and beyond, combining raw international espionage, classified satellite reports, weaponized mineralogy, advanced underground mapping techniques, and every gear-head’s camping equipment fantasy turned up to 11.

La vie minérale

[Image: Photo by Virginie Laganière and Jean-Maxime Dufresne].

A new exhibition featuring photos, videos, and sound installations by Virginie Laganière and Jean-Maxime Dufresne looks at life underground in Helsinki, Finland.

“Imagine a city with more than 400 underground facilities, tunnels that span over hundreds of kilometres and 10 million cubic meters of space carved into old Precambrian bedrock,” they write. These spaces serve as “athletic training sites, energy distribution networks, globalized data centers, archival chambers, a buried church or undisclosed military facilities,” to name only a few of their everyday uses.

The exhibition is up until June 17th, in Québec City. Read more at l’Œil de Poisson.

Devotional Speleology

[Images: Photo by BLDGBLOG].

I’ve been traveling around London, the Adriatic, and the Mediterranean Sea the past few weeks, doing research for a new book, and thus not really using the internet outside of a bunch of Instagram shots; nonetheless, I thought I’d post some pictures from the trip.

Here, above, is Nicola Twilley peering into an old devotional cave dwelling on the Marjan peninsula outside Split, Croatia.

[Image: Photo by BLDGBLOG].

The hermitage is up in a cliff behind a church dedicated to St. Jerome, and the whole complex apparently dates back to the 15th century.

The church itself is also quite picturesque among the trees, with a nearly panoramic view of the Adriatic.

See many more general travel shots on Instagram.

Subterranean Robotics on Other Worlds

pavonis-mons-skylight [Image: Possible cave entrance on Mars, via space.com].

There was an interesting article in last month’s issue of Air & Space about the design of subterranean robotics for exploring caves on other planets.

It primarily looks at “a robot called LEMUR, short for Limbed Excursion Mechanical Utility Robot.” LEMUR, we read, “is designed to climb the porous walls of a cave 150 million miles away, on Mars.”

lemur
[Image: The LEMUR robot in action; photo by Aaron Parness/JPL via Air & Space].

The article goes on to discuss the work of speleobiologist Penelope Boston, who you might remember from a long interview here on BLDGBLOG (originally recorded for Venue), as well as the challenges of sample-return missions, how robots might go spelunking on other planets, and more.

Check it out in full.

Schrödinger’s Speleology, or the Stalking of “Entranceless Caves”

[Image: A cave entrance in France, via Wikipedia].

I recently finished reading Last Words by Michael Koryta, a detective novel largely centered on an unmapped fictional cave system in southern Indiana, part of the great karst belt near the border with Kentucky.

One interesting thing about the novel is that this cave, known in the book as “Trapdoor,” operates on many different narrative levels. Most obviously, of course, there’s the unreliable memory of a major character suspected—yet never officially accused—of committing a murder there, where the darkness of Trapdoor’s linked subterranean spaces becomes a kind of mental model for his own inability to recall what really happened, when a woman was (apparently) murdered in the cave’s depths.

There is also a subplot, though, revealed quite late in the book, in which disguised real estate deals and obscure land trust deeds have been premised on the subterranean potential of this land snaking along the region’s old creeks and rivers, transactions inked with the belief that Trapdoor’s passages might continue beneath distant parcels; in this way, the cave comes to represent the conspiratorial intentions of people otherwise unwilling to state their true goals.

Finding the true outer limits of the cave—that is, finding the land parcels that the cave secretly connects from below—becomes coextensive with discovering the truth about what occurred underground there so many years earlier.

[Image: Cave in Venezuela, photographed by Vittorio Crobu, courtesy European Space Agency].

It was these latter parts of the novel—including a handful of plot points I won’t get into—that reminded me of notes I’d taken from a book called the Encyclopedia of Caves several years ago. That book includes a short entry written by Nevin W. Davis, called “Entranceless Caves, Discovery of.”

As Davis describes them, “entranceless caves” are like speleological versions of Schrödinger’s cat: they exist, but they have not been verified. They are real—but perhaps not. They are both in the ground and nowhere.

At times, Davis’s text is almost like a koan: “Suppose the cave is totally unknown and has no entrance,” he writes. What exactly is such a thing, and how can we account for its presence (or absence) in the landscape? After all, these are caves that have not been—and perhaps cannot ever be—located.

He goes on to describe mathematical models used to generate a probability of subterranean connection: the calculated likelihood that physically inaccessible voids might exist beneath the surface of things, linking one part of the world to another.

[Image: Cave in Mexico, photographed by Vittorio Crobu, courtesy European Space Agency].

“Another consideration in searching for caves,” Davis continues, “is entrance lifetime. Caves are long-term features under the landscape with lifetimes measured in millions of years, whereas entrances to them are fleeting features with lifetimes measured in millennia.”

Cave entrances come and go, in other words, while the caves they once led to remain. They can be covered over, woven shut by tree roots, erased.

As Davis describes it, “leaves and twigs will soon cover and block small vertical entrances. Pits less than a meter in diameter”—tiny holes that can nonetheless lead to huge systems, such as the real-life Mammoth Cave or the fictional Trapdoor—“can be totally blocked in one season. Leaves blocking a small entrance are soon followed by roots and more leaves and it is not long before all traces of an entrance are gone.”

This leads to an activity he calls “stalking the elusive entranceless cave”—which, for what it’s worth, seems like a perfect metaphor for part of Koryta’s novel, in which the book’s amnesia-stricken potential murderer undergoes hypnosis. His memory is a cave with no entrance.

[Image: Cave in Venezuela, photographed by Vittorio Crobu, courtesy European Space Agency].

In any case, there can also be “false positives,” Davis warns. These would be caves that appear to have been detected but that are not, in fact, real. A “stalker” of previously unknown caves might find herself misled by patches of melted snow, for example, or by other signs that wrongly give the impression of warm air rising from empty passages below.

“The best condition to search for snow melt,” Davis suggests, instead, “is with a new snowfall in midwinter with an overcast sky, since sunlight can also give false positives by shining through snow cover onto rocks and melting the snow. This is a tried-and-true method that has led to countless new caves.” It’s cave-discovery weather.

In essence, this is a process of reading the landscape: interpreting its surface features in order to gain knowledge of these other, deeper dimensions.

[Image: An artificially enlarged entrance to Carlsbad Caverns; Instagram by BLDGBLOG].

The next entry in the Encyclopedia is also worth reading; it is simply called “Entrances,” by William B. White. “Some caves,” White writes, continuing the strangely existential thread of Davis’s work, “may have no entrances at all.”

White adds a new category here, what he calls the “concealed entrance.”

At least from an architectural point of view, what’s interesting is that this allows White and other speleologists to challenge the idea of there being a clean dividing line between inside and outside, between a cave and the Earth’s surface.

Instead, he suggests, a cave’s entrance should actually be thought of as a transition: the “cave entrance zone,” White writes, “is, in effect, a continuous sequence of microclimates,” one that eventually leads to a point at which there is no direct access to sunlight or to rainfall.

It is only at that point that you are truly “inside” the Earth. You have transitioned to the great interior.

[Image: Photographer unknown; image via Discovery Communications].

Briefly, White also points out that cave entrances are not only unstable in the temporal sense—as Davis mentioned, cave entrances can completely disappear over time.

However, they are also unstable spatially: that is, they can physically migrate through the landscape over thousands, or even tens, of years.

Due to continual rockfall, for example, a cave entrance “not only migrates deeper into the hill but also migrates upward as rocks break away,” Davis writes. This can potentially push a cave entrance dozens and dozens of feet from its original location, while the cave itself remains stationary. Imagine a mouth migrating across your body while your stomach stands still.

Of course, this also means that an entrance to a given cave system can abruptly migrate onto someone else’s property, or that it can even pop open, suddenly and dramatically changing the value of a particular piece of land.

The next thing you know, following an unusually intense summer rainstorm, you own the entrance to a cave.

[Image: A salt cave in Israel; image via Wikipedia].

Which brings us back to Michael Koryta’s novel. There, an unexpected opening into the unstable depths of Indiana’s fictional Trapdoor complex changes the lives of many characters not just for the worse, but for the tragic.

The cave, as Koryta depicts it, is a relentless and unsympathetic thing, a space always shifting, growing organically but not alive, invisible yet ubiquitous, moving beneath the surface of the landscape, connecting parcels of land, as well as the lives—and deaths—of the characters who thought they were just idly passing time above.

The Voids Beneath

[Image: Drone footage of a Cornwall garden sinkhole, via the BBC].

One of the peculiar pleasures of reading Subterranea, a magazine published by Subterranea Britannica, is catching up on British sinkhole news.

In more or less every issue, there will be tales of such things as “a mysterious collapse in a garden behind a 19th-century house,” that turns out to be a shaft leading down into a forgotten sand mine, or of “abandoned chalk mine sites” heavily eroding in winter rain storms, “resulting in roof-falls.”

“As most chalk mines are at relatively shallow depth,” Subterranea reports, “these roof-falls migrate upwards to break [the] surface as ‘crown holes’ or craters, which in the said winter [of 2013/2014] have been appearing in lawns and driveways, and even under houses, newly built in chalk districts.”

The earth deceptively hollow, the landscape around you actually a ceiling for spaces beneath.

Worryingly, many of these mines and underground quarries are difficult, if not impossible, to locate, as insufficient regulation combined with shabby documentation practices mean that there could be abandoned underground workings you might never be aware of hiding beneath your own property—until next winter’s rains kick in, that is, or the next, when you can look forward to staring out at the grass and shrubbery, with growing angst, waiting for sinkholes to appear. Rain becomes a kind of cave-finding technology.

Even in the heart of London, the underworld beckons. Last Spring, Subterranea reminds us, “a woman and her shopping trolley rather suddenly disappeared into a four metres deep hole in North End Road, Fulham.” The culprit? It “appears to have been a disused under-street coal cellar.”

Perhaps the most incredible recent example, however, comes from the town of Scorrier, in Cornwall.

shaft [Image: Photo courtesy The Sun].

There, a “deep mine shaft has appeared” beneath the patio of a house in the process of being prepped for sale. “The shaft drops approximately 300 feet deep to water but could be four or five times deeper [!] below that,” Subterranea reports. It “is a remnant of Cornwall’s tin mining industry in the 18th century.”

It is a straight vertical shaft, more like a rectangular well, yawning open behind the house.

And there are many more of these mines and quarries, still waiting to be discovered: “As mines closed,” we read, “many [mining companies] put very large blocks of timber, often old railway sleepers, across shafts and backfilled them, thinking this would be safe. Gradually all evidence of the engine houses and covered shafts disappeared from view and memory and in the past builders assumed there was nothing there. Had they consulted old maps they would have known about the shaft. The timbers rotted over the years and collapses like this often happen after long periods of rain, which they have had in this area.”

There’s something both uncanny and compelling about the idea that, with seasons of increased rainfall due to climate change, the nation’s mining industry might stage an unsettling reappearance, bursting open in subterranean splendor to swallow the surface world whole.

Think of it as an industrial-historical variation on the El Niño rains in Los Angeles—where huge storms were suspected of “unearthing more skeletal human remains” in the parched hills outside the city—only here given the horror movie ambience of murderous voids opening up beneath houses, making their abyssal presence felt after long winter nights of darkness and endless rain.

In any case, consider joining Subterranea Britannica for a subscription to Subterranea for more sinkhole news.

Colossal Cave Adventure

[Photo: “Mega Bike” at the Louisville Mega Cavern; photo courtesy Louisville Mega Cavern].

An underground bike park is opening up next month in a former limestone mine 100 feet beneath Louisville, Kentucky.

At 320,000-square feet, the facility is massive. Outside Magazine explains, “the park will have more than five miles of interconnected trails that range from flowing singletrack to dirt jumps to technical lines with three-foot drops. And that’s just the first of three phases to roll out this winter.”

[Photo: “Mega Bike” at the Louisville Mega Cavern; photo courtesy Louisville Mega Cavern].

That’s from an interview that Outside just posted with the park’s designer, Joe Prisel, discussing things like the challenges of the dirt they’ve had to use during the construction process and the machines they used to sculpt it.

[Photo: “Mega Bike” at the Louisville Mega Cavern; photo courtesy Louisville Mega Cavern].

It’s not the most architecturally-relevant interview, if I’m being honest, so there’s not much to quote here from it, but the very idea of a BMX super-track 10 stories underground in a limestone mine sounds like a project straight out of an architecture student’s summer sketchbook, and it’s cool to see something like this become real.

Military Cave Logistics

[Image: “Humvees are stored inside the Frigaard Cave in central Norway. The cave is one of six caves that are part of the Marine Corps Prepositioning Program-Norway, which supports the equipping of Marine Expeditionary Brigade consisting of 15,000 Marines and with supplies for up to 30 days.” U.S. Marine Corps photo by Lance Cpl. Marcin Platek].

Norwegian caves are being stuffed full of U.S. military equipment, including armored Humvees, tanks, and cargo containers full of weaponry, all part of a vast and semi-subterranean supply chain maintained to help wage future wars around the world.

The Marines have “stashed weapons and equipment in the Norwegian countryside since the 1980s,” War is Boring explains, in sites that include artificially enlarged and fortified caves. It’s all about logistics: “With this setup, Marines can fly in and be ready for a fight in no time.”

[Image: “Rows of front loaders and 7-ton trucks sit, gassed up and ready to roll in one of the many corridors in the Frigard supply cave located on the Vaernes Garrison near Trondheim, Norway. This is one of seven [see previous caption!] caves that make up the Marine Corps Prepositioning Program-Norway facility. All the caves total more than 900,000 sq. ft. of storage space, full of enough gear to outfit 13,000 Marines for up to 30 days.” U.S. Marine Corps photo by Sgt. Matt Lyman].

These facilities are commonly described as “supply caves,” and they hold warfighting gear in a state of indefinite readiness, “reserved for any time of crisis or war.”

Marines can simply fly in, unlock their respective caves, and grab the keys to one of hundreds, if not thousands, of combat-ready vehicles, all “gassed up and ready to roll in one of the many corridors” of this subterranean empire on the edges of American influence.

Among many other points of interest, the Marines identify six such supply caves in the caption of one image and seven caves in the caption of another, as if—assuming this is not just a minor clerical error—the Marines themselves don’t even know how many caves they have.

Instead, there’s just Norway, some faraway land of underground voids we’ve stuffed full of combat gear, like emperors stocking our own tombs in advance of some future demise—the actual number of caves be damned, for who will be left counting at the end of the world?

[Image: “Medium Tactical Vehicle Replacements, High Mobility Multipurpose Wheeled Vehicles and trailers, which belong to Marine Corps Prepositioning Program-Norway are staged in a storage cave at Tromsdal, Norway, Feb. 24, 2014. Marine Corps began storing equipment in several cave sites throughout Norway in the 1980s to counter the Soviets, but the gear is now reserved for any time of crisis or war.” U.S. Marine Corps photo by Lance Cpl. Sullivan Laramie].

On one level, I’m reminded of Marcus Trimble’s old joke that France has been constructing a back-up version of itself in China. It is a frenzied act of “pre-emptive preservation,” led by the cultural ministers of that sclerotic nation of well-tended chateaux who realized that la belle France could only survive if they built immediately ready copies of themselves elsewhere.

Only, in France’s case, it wasn’t willful self-burial in Norwegian caves, but in the real estate free-for-all of urban China. After all, Trimble suggested, that country’s “construction industry seems perfect for the task of backing up bricks rather than bits—cheap and powered by the brute force of sheer population. Copies of places may be made in a fraction of the time that it took to create them. If, in the event of a catastrophic episode, the part of France in question could be restored and life would go on as it was before.”

[Image: “China: ample space for a spare copy of France”; image by Marcus Trimble].

Militarize this, secret it away in a cave in Scandinavia, and you have something roughly approximately what’s called the Marine Corps Prepositioning Program.

However, I was also reminded of a recent paper by Pierre Belanger and Alexander Scott Arroyo at Harvard’s GSD. There, Belanger and Arroyo describe the U.S. military as a kind of planetary logistics challenge. (A PDF of their paper is available here courtesy of the U.S. Department of Defense).

Specifically, it is the problem of building and often violently maintaining “logistics islands,” as Belanger and Arroyo describe them, that now characterizes much of the U.S. military’s global behavior, an endless quest for finding and protecting “a secure staging ground adjacent to the theater of operations,” in an era when adjacency is increasingly hard to define. As they explain:

While logistical acquisitions are managed by the Defense Logistics Agency (DLA), logistical operations in the field are predominantly coordinated by USTRANSCOM. On average, the command oversees almost 2,000 air missions and 10,000 ground shipments per week, with 25 container ships providing active logistical support. From October 2009 through September 2010 alone, USTRANSCOM flew 37,304 airlift missions carrying over 2 million passengers and 852,141 tons of cargo; aerially refueled 13,504 aircraft with 338,856,200 pounds of fuel on 11,859 distinct sorties; and moved nearly 25 million tons of cargo in coordinated sea-land operations. DLA and USTRANSCOM and their civilian partners are responsible for the largest, most widespread, and most diverse sustained logistics operation in history.

The largest, most widespread, and most diverse sustained logistics operation in history.

The obvious and intended resonance here is that military operations perhaps now most closely resemble complicated UPS deliveries than anything like actual ground combat. However, we can also infer from this that establishing new and ever more convenient logistics islands is vital to U.S. national security.

A literal archipelago of shipping hubs is thus key to the country’s global military activities, and this not only requires sites like Diego Garcia, which Belanger and Arroyo specifically write about, or even the “mobile offshore bases” they also describe, where the pop-up urbanism of Archigram has been inadvertently realized by the U.S. military, but artificially fortified caves near the Arctic Circle where truly daunting amounts of military materiel are now kept on hand, as if held frozen in some imperial freezer, awaiting the day when global tensions truly heat up.

Read a bit more at War is Boring.

(This is more or less irrelevant, but you might also like Kiln, earlier on BLDGBLOG).