This story originally appeared in the August 2014 issue of National Geographic magazine as "The Hidden World of the Great War." In honor of Veterans Day and the 100th anniversary of the end of World War I, it has been updated with vintage National Geographic photographs, which ran in the magazine's original 1917 coverage of the First World War.
The entrance is a wet hole in the earth little bigger than an animal burrow, obscured by thorny brush in a secluded wood in northeastern France. I’m following Jeff Gusky, a photographer and physician from Texas who has explored dozens of underground spaces like this one. Together we slither through the muddy hole into the darkness below. Soon the passage opens up, and we crawl forward on hands and knees. The glow from our headlamps wavers along the dusty chalk walls of the century-old tunnel, which slopes away from us down into the shadows. After a few hundred feet the tunnel ends at a little cubicle hewed out of the chalk, reminiscent of a telephone booth.
Here, shortly after the outbreak of the First World War—which began a hundred years ago this summer—German military engineers would take turns sitting in total silence, listening intently for the slightest sound of enemy tunnelers. Muffled voices or the scraping of shovels meant that a hostile mining team might be only yards away, digging an attack tunnel straight toward you. The danger grew if the digging stopped and you heard the sound of bags or cans being quietly stacked, one on top of another. It signaled that the enemy was laying high explosives at the end of the tunnel. Most nerve-racking of all was the silence that followed. At any moment the charges might detonate and blow you apart or bury you alive. (See how World War I energized mapmaking at National Geographic.)
Nearby, on one of the tunnel walls, our headlamps illuminate graffiti left by the German engineers who manned this listening post. Their inscribed names and regiments are crowned by a motto: “Gott für Kaiser! (God for the Kaiser!).” The pencil marks appear fresh, as if they were written yesterday. In fact, the soft chalk and limestone bedrock of France’s Picardy region was ideal not only for mining operations but also for World War I soldiers to record their presence in penciled signatures, sketches and caricatures, carvings, and even intricate relief sculptures. This underground art is relatively unknown beyond a circle of World War I scholars and enthusiasts, as well as village mayors and landowners, many of whom Gusky has spent years getting to know.
His images bring to light the subterranean world soldiers endured while sheltering from constant shellfire. They left names, images of women, religious symbols, cartoons, and more. These traces, Gusky says, illuminate a forgotten world of World War I, connecting us to the individual soldiers, many of whom would not survive the nightmare of trench warfare.
The conflict began with mounted cavalry and confidence on all sides that it would all be over by Christmas. By the end of 1914 the German advance had stalled, the armies had dug in, and an extensive network of trenches stretched from the North Sea coast to the Swiss border. An arms race led to the first mass use of poison gas, air warfare, and tanks. On the western front, millions of troops died in largely futile offensives and counterattacks. (National Geographic's guide to the sites along Europe's Western Front.)
In the grip of this deadly stalemate, the Germans and their French and British adversaries resorted to siege-warfare techniques that had changed little over the centuries. The goal was to dig under key enemy strongpoints and blow them up; counterattacks were thwarted by setting off charges to destroy their own tunnels. At the height of the underground war, in 1916, British tunneling units detonated some 750 mines along their hundred-mile sector of the front; the Germans responded with nearly 700 charges of their own. Hills and ridges that provided vital lookout points became riddled like Swiss cheese, while the biggest mines blew out huge craters that still scar the landscape to this day. Even a single small mine could wreak havoc: In the tunnel complex we crawled into, a charge set off by the Germans on January 26, 1915, killed 26 French infantrymen and wounded 22 more.
But the underground war was not confined to narrow tunnels. Beneath Picardy’s fields and forests are centuries-old abandoned quarries, some of which could shelter thousands of troops. On a misty morning we explore one such site, located along a cliff edge overlooking the Aisne Valley. We’re led there by the owner of the ancestral property, which we agree not to name to protect the quarry from vandals.
He proudly shows us a monumental carving of Marianne, the classic French symbol of liberty, guarding the entrance to the quarry. Beyond, in the gloom of the man-made cavern, we peer at an array of finely engraved badges and memorials proclaiming the French regiments that had sheltered here. And we come upon several chapels elaborately carved and painted with religious symbols, army insignia, and the names of notable French victories. The landowner shows us a stone stairway that led from one of the chapels to the fury of exploding shells and machine-gun fire in the front lines above. “My heart stirs when I think of all the men who climbed these steps and never came back,” he says.
Life in the quarries was vastly preferable to the muddy hell of the trenches above. A journalist visiting one of the caverns in 1915 noted that “a dry shelter, straw, some furniture, a fire, are great luxuries for those returning from the trenches.” They kept an even temperature year-round, but as one French soldier wrote home, “vermin devour us, and it’s teeming with lice, fleas, rats and mice. What’s more, it’s very humid and a lot of the men fall sick.” To pass the time, the exhausted men would daydream. Images of women proliferate on the quarry walls, including many sentimental and idealized portraits.
Both sides converted the largest quarries into underground cities, many of them remarkably intact today. Not far from the landowner’s property, we hike across the potato fields of a farm owned by his cousin. A young man in his 20s, he had reclaimed the land by personally collecting dozens of unexploded mortars, grenades, and shells, some containing still lethal poison gas, which the army took away and detonated.
Beneath his potato field, we find ourselves in an astonishing labyrinth, a medieval quarry that stretches for more than seven miles, with twisting passageways and high ceilings reminiscent of a subway station. In 1915 the Germans connected this vast warren to their frontline trenches. They installed electric lights and telephones, command posts, a bakery and butcher’s, a machine shop, a hospital, and a chapel. Although thick with rust, the original diesel generator and barbed wire defenses are still in place. So are dozens of street signs neatly stenciled on every corner, essential reference points in the disorienting maze of passages. On the cavern walls German troops have inscribed their names and regiments, religious and military icons, elaborately sculpted portraits and caricatures, and sketches of dogs and other cartoons. (Learn about important part animals played in World War I.)
Among the most prolific decorators of the underground cities was the 26th “Yankee” Division, one of the first U.S. units to reach the front following America’s entry into the war in April 1917. To visit the quarry where they were billeted at Chemin des Dames, we climb down two wobbly ladders into a cavern 30 feet below. We spend hours exploring a hundred-acre complex. Our headlamps reveal an extraordinary time capsule of the war: passageways strewn with countless bottles, shoes, shell cases, helmets, beds made of rusted chicken wire, even an entire cooking range with pots and pans still in place.
For six weeks beginning in February 1918, these passages were filled with the sounds and smells of hundreds of American men. Mostly raw recruits, they were rotated in and out of the quarries to their first experience in the trenches above. The men spent hours decorating every square inch of certain walls. We pick out dozens of religious and patriotic symbols: insignia of the Freemasons and Knights of Columbus; portraits of Uncle Sam, Buffalo Bill; and caricatures of the kaiser. Among the penciled names my eye falls on is “Earle W. Madeley,” a corporal from Connecticut who notes he is “aged 20 years.” Records show Madeley was killed on July 21, 1918, one of 2,000 deaths inflicted on the Yankee Division before the November armistice.
Safe underground from the inhuman chaos of the battlefield above, the men of the First World War left these personal expressions of identity and survival. But this unique heritage from the war is under threat. When vandals tried to saw off the image of Marianne, the outraged landowner fitted metal bars on all of his quarries. At the Yankee Division quarry, a retired auto mechanic dedicated to safeguarding it built hefty metal gates and installed padlocks. But many other sites remain at risk from vandals and thieves.
The auto mechanic secures the lock, and we walk back to the car. As the bitter January wind blows across the battlefield, I ask him why a quarry filled with American names is so important to him. He reflects for a second, then replies, “By reading the names of the men down there, we make them live again, for a moment.”