Greetings from Cercen Pass. It is storming and snow covers the highest peaks. We wait for peace, but the bad weather, the high altitudes ... Peace can only come with our death.

—from the May 28, 1916, diary of C.D., a soldier from Italy's Trentino region

The first cold war was fought during the First World War.

Italian and Austro-Hungarian troops clashed at altitudes up to 12,000 feet (3,600 meters) with temperatures as low as -22°F (-30°C) in the Guerra Bianca, or White War, named for its wintry theater. Never before had battles been waged on such towering peaks or in such frigid conditions.

Now, a century later, the warming world is revealing the buried past, as relics and corpses are melting free of their icy tombs.

Italy began the war on May 23, 1915. Its aim, stoked by a rising nationalist fervor, was to annex several regions—particularly those inhabited by Italians—held by the Austro-Hungarian Empire.

Troops fought and died all along the frontier, from Trentino to the Adriatic, for the next three years. Perhaps most remarkable, though, was the White War, a series of impossible—and ultimately futile—blitzes, incursions, athletic feats, and engineering coups.

Working in brutal conditions, Italians and Austro-Hungarians alike leveled peaks, opened roads, dug tunnels, built cableways, laid telephone lines, and transported tons of material to lofty heights—for combat, but also for the everyday needs of the thousands of soldiers who were living year-round at altitudes where only shepherds, wild herb hunters, and mountain climbers had ever ventured.

High-Altitude Front Line

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Entire villages of shacks were built, though officers generally lived in old mountain refuges, some outfitted with grand pianos and gramophones. On Marmolada, the highest mountain in the Dolomites, the Austrian Corps of Engineers built an entire "ice city"—a complex of tunnels, dormitories, and storerooms dug out of the bowels of the glacier.

Even so, they could do only so much against the unforgiving elements.

"In accounts of the period, in war diaries—whether they be Austrian or Italian—we find the same stories of the terrible hardship caused by the lack of sleep, the torments, and the massive snowfalls," says Stefano Morosini, a researcher at the University of Milan and author of a book on the history of Italian mountaineering. "The enemy took second place. Indeed, the true adversary was nature herself."

View Images Austro-Hungarian soldiers march through the snow. In war diaries and other accounts of soldiers from both sides, "We find the same stories of the terrible hardship caused by the lack of sleep, the torments, and the massive snowfalls," says Stefano Morosini, author of a book on the history of Italian mountaineering. Photograph courtesy Museo Storico Italiano Della Guerra Di Rovereto

Marco Balbi, founder and president of the White War Historical Society, says that only about one-third of the 150,000 men who died on the Alpine front were victims of battle. The rest were killed by avalanches, landslides, frostbite, and illnesses caused by the extreme cold.

Fight at a Front-Line Site

"Cavento! Tower of loyalty frozen in deep ice. Around you burn the wildfires of the proud enemy. High up you rise, Corno di Cavento, a warning cry to the cowardly!"

—from the April 3, 1917, war diary of Austro-Hungarian Lieutenant Felix Hecht von Eleda

Some of the most critical fighting took place on the 11,051-foot-high (3,368 meters) Corno di Cavento. Its eastern slopes rise gently along the Vedretta di Lares glacier. To the west, the mountain face plummets straight down to the valley.

After the first offensive of the Alpini—the Italian mountain-warfare military corps—in April 1916, Corno di Cavento became the front line of the Austrian defense.

In February 1917, Kaiserjäger Lieutenant Felix Hecht von Eleda, a highly religious 23-year-old officer from Vienna, assumed command of the garrison. His aim was to reinforce defenses and import heavy artillery. Following his orders, "diggers" from the Austro-Hungarian Corps of Engineers, aided by Russian prisoners, blew up outlying rocks with explosives and dug a tunnel into the summit of the mountain.

View Images A vintage photograph of an Adamello lookout post shows the treacherous aspects of war at high altitudes. Photograph courtesy Museo Storico Italiano Della Guerra Di Rovereto

It was a truly Sisyphean labor: Snowfall destroyed weeks of work, the Russian prisoners escaped, and many of the Austro-Hungarian soldiers collapsed from the cold or were injured by mines. With temperatures hovering well below zero, nocturnal reconnaissance missions were both an adventure and torture.

Adding to the tension was the anticipation of combat with the "Tigers," as the Austro-Hungarians called the Alpini. Hecht writes that as blasts of enemy artillery startled him, he could sometimes make out their white uniforms against the snow.

On June 15, 1917, about 1,500 Alpinis attacked Corno di Cavento from three sides, routing much of Hecht's garrison. The lieutenant was killed as he emerged from the relative safety of the gallery to try to prevent soldiers from fleeing.

One of the attackers—Italian Captain Fabrizio Battanta, known as the "Cavento Bandit"—found Hecht's diary and took it with him. (Hecht's special shorthand was deciphered, translated, and published years later. Today, the original is kept in a museum in Spiazzo.) Hecht's body, most likely thrown into a crevasse, has never been found.

View Images Soldiers drill holes into the ice to place explosives and begin the massive task of digging a tunnel under enemy lines. In the Dolomites, the Austrian Corps of Engineers dug an entire "ice city"—a complex of tunnels, dormitories, and storerooms—out of the glacier. Photograph courtesy Museo Storico Italiano Della Guerra Di Rovereto

In June 1918 the Austro-Hungarians, emerging from a tunnel they'd dug through the glacier, took back Corno di Cavento. But later that month the Italians returned in force and managed to recapture the summit. This time they held it until the end of the war. The last garrison of Alpini left Corno di Cavento a few weeks after the Armistice of Villa Gusti took effect November 4, after which thousands of soldiers returned home.

Salvaging History

After the troops departed, the glaciers were deserted once again. The only people who ventured there were "salvagers"—men who hiked up to collect leftover war materials, mostly metal, to resell by the pound. The most sought-after items were the copper, brass, and lead inside large, unexploded bombs.

"We brought a mallet with us and would pound the bomb at a very precise point so that the casing would break away," 92-year-old Giacinto Capelli, one of the last salvagers, recalled before passing away recently. "If we made a mistake, the powder left inside could have exploded in our faces. It was such hard work. We went back down the mountain with as many as 70 kilos [150 pounds] on our backs. But there was no work in the village, and salvagers made good money. The first time I came home with 320 liras, my father jumped for joy, crying, 'Now we can have polenta all year long!' "

View Images A grenade shell used as a lamp hangs inside a deep passageway in a Corno di Cavento garrison. The Austrians dug the military post into the rock; the Italians conquered it twice. The cave is now accessible to visitors. Photograph by Stefano Torrione, National Geographic-Italia

The White War artifacts found by salvagers such as Capelli have seeded several small museums. And the memory of the war continues to be a powerful draw for hikers and history enthusiasts. Luckily, Corno di Cavento holds almost perfectly preserved vestiges of emplacements, communication trenches, barbed-wire fences, embrasures, and shacks.

And thanks to climate change, relics from the war are continuing to re-emerge. The glacier is on the move, retreating as it melts. Fifteen years ago climbers who ventured up Corno di Cavento discovered that it was becoming possible to access the Austro-Hungarian garrison once again.

"We knew it was there. We had our eye on it," says Marco Gramola of the Società degli Alpinisti Tridentini (SAT), Trentino's alpine club. "Since the turn of the century we have begun to restore the Austrian posts. In 2005, we took 80 people to the summit as part of a large protest, calling on the government to intervene. The memory of the White War was in danger of being lost both through neglect and through plundering by collectors and private dealers."

It took four summers, from 2007 through 2010, to reopen the gallery, thanks to the combined efforts of SAT volunteers and local government agencies.

After workers from those organizations excavated a tunnel in the ice, they used a massive heat conveyor to illuminate a space—203 feet (62 meters) long, 16 feet (5 meters) wide, and 10 feet (3 meters) tall, which was big enough to house 40 soldiers—in precisely the same state it had been in more than 90 years ago. Straw bunk beds, a storeroom, a telephone operator's station, a commander's small office with a desk, a large metal stove, even a stack of wood to heat the space—it was all there.

"It was like walking into an enormous defrosted refrigerator," says Gramola. "On the floor lay bits of food, dirty swabs, bandages, and quantities of relics—not just bullets, helmets, and military equipment, but the soldiers' personal belongings as well."

There was also a bag of dirty laundry, a deck of cards, a sewing kit, and a little mirror with a woman's photo.

View Images Italian troops congregate around a mountain refuge. During WWI, for the first time in history, men brought modern technology up the highest mountains, building roads, cableways, telephone and electric lines, and accommodations for thousands of troops. Much of the equipment had to be carried by hand. Photograph courtesy Museo Storico Italiano Della Guerra Di Rovereto

"We catalogued and photographed every item," says Gramola, "just like at an archaeological site. For a while, we kept them in a freezer lent to us by an ice-cream maker from the valley to keep them from deteriorating."

The Smell of History

Today the space can be visited by hikers capable of making the climb up the mountain. Last summer the Austro-Hungarian post at Punta Linke—a station for the cableway that's 11,916 feet (3,632 meters) above sea level, on Mount Vioz—also opened to the public.

That recovery operation is being coordinated by Franco Nicolis, director of the Archaeological Heritage Department of the Province of Trentino.

"Archaeology does not only concern the ancient world," Nicolis says. "There is also what I like to call 'grandfather archeology' ... [in which the goal is] to reconstruct a space and the life of the men who lived there.

View Images War memorabilia is still being discovered on the Alpine frontier, shedding light on the lives of the soldiers from both sides, including a gas mask, hat, and glacier glasses (left) and a cross made out of barbed wire (right). Photographs by Stefano Torrione, National Geographic

"What struck me most about Punta Linke," he adds, "were the smells—of wood, of the tar paper used for insulation, of the motor oil for the cableway. The sense of smell is a primal one, an almost animal sense that can serve as a time machine to transport us back 100 years in an instant."

Cold Casualties

Corno di Cavento and Punta Linke are only a couple of the hundreds of sites being readied for the World War I anniversary. As the world continues to warm, more may soon come to light as well.

"In the last century and a half," says Christian Casarotto, a glaciologist at the MUSE science museum in Trento, "the Adamello Glacier has retreated 2 kilometers [1.2 miles]. At the lowest-altitude points, up to 4 meters [13 feet] of thickness is lost every year."

View Images At left: A framed mirror holds a woman's portrait. At right: An oil lamp. Photographs by Stefano Torrione, National Geographic-Italia

The thawing is revealing more than artifacts. Corpses—unknown soldiers, victims of battles or a random bullet, an avalanche, a careless step—are melting free of their icy tombs. That includes two Austro-Hungarian soldiers, probably killed by a grenade, whose bodies were discovered in 2012 on the Presena Glacier.

Nicolis, who participated in the recovery of those remains, says the soldiers "were at the bottom of a crevasse, thrown there by Italian soldiers, or by their own fellow soldiers, or perhaps by some salvager. But not before their boots and every other useful object were taken.

"One of them still had a spoon, though, wrapped in the puttee around his leg. This was a common practice: In war, soldiers never knew when they would eat, so they carried their spoons everywhere, just like their toothbrush."

Both soldiers, says Daniel Gaudio, a forensic anthropologist in Vicenza, "were very young—about 18 years old."

Gaudio has examined more than 50 corpses from the White War. But "unfortunately," he says, "without a name tag, it is unlikely that they can be identified. The DNA from a body conserved in the ice can be extracted rather easily, but then it should be compared to a database of the entire population—which of course does not exist.

View Images Makeshift housing used by Austro-Hungarian soldiers can still be seen on Caré Alto in the Adamello region. Soldiers often lived year-round in such dire—and precarious—conditions. Photographs by Stefano Torrione, National Geographic-Italia

"Nonetheless," he adds, "we usually manage to reconstruct a sort of micro-history of the soldier: height, age, and the presence of pathologies. Almost all of them have a herniated disk or other signs of stress to the spinal column, [usually] found today in individuals over 50. This means that they performed heavy work, probably as farmers. And so many of them had serious cavities and abscesses. They fought while suffering from pain that we would consider intolerable today."