The French labelled it a 'Zone Rouge' shortly after the end of the war, leaving it to be reclaimed by nature

At its end in December of that year, the French victorious, an area larger than the city of Paris had been destroyed

The battle for Verdun in 1916 was the longest in history, with millions of shells fired over 10 months


The forest in northern France appears almost fairytale-like like in its eerie calm.

But the apparently lush ground hides a deadly secret: underneath this green carpet lies lethal levels of arsenic, unexploded bombs, tracts of barbed wire and the remains of the men who gave their lives fighting for control of this strip of land almost 100 years ago.

The forest is so dangerous that swathes of it have been declared a no-go zone, where trees no longer grow, and only the brave or foolish have dared tread in the 97 years since the end of the First World War.

For the forest, and countryside surrounding it, was the site for the Battle of Verdun, the longest in history, now categorised as a 'Zone Rouge' - still toxic after all this time.

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Battle scars: They might look like soldiers, but these men are searching for shells which were fired almost a century ago

Deadly: There are still areas which are blocked off because of the high levels of poison still seeping through the land

Poisoned: The damage was done by the millions shells filled with arsenic fired during the Battle of Verdun during the First World War

Memories: The land is still pockmarked with the trenches and craters left behind after the fierce fighting

Danger: The barbed wire which prevented either side making a clean break across no-mans land still lies on the ground

Memorial: After decades of peace, the forest is a lasting reminder of the damage the First World War did - to lives lost and the landscape

Clean up operation: Retired forest services worker Daniel Gadois walks past German 77mm and 105mm artillery shells which were never fired that he collected and marked in orange paint for later disposal in Bois Azoule forest

Blood-letting: This was a true battle of attrition - the Germans were trying to 'bleed the French white'

Few could have imagined, when the Germans stormed the town of Verdun, near the border with Belgium, on February 21, 1916, what the repercussions would be down the generations.

On the first day alone, the Germans - who sent 140,000 soldiers to attack the French town at the start - had 1,000 guns pummeling the earth, and the French soldiers.

The aim, said Erich von Falkenhayn, the German chief of the general, was to 'bleed the French army white'.

One French officer recalled: 'When the first wave of the assault is decimated, the ground is dotted with heaps of corpses, but the second wave is already pressing on.

'Once more our shells carve awful gaps in their ranks... Then our heavy artillery bursts forth in fury. The whole valley is turned into a volcano, and its exit blocked by the barrier of the slain.'

Another remembered how the 'men were squashed. Cut in two or divided from top to bottom. Blown into showers; bellies turned inside out; skulls forced into the chest as if by a blow from a club'.

This would continue for another 300 days: when it ended, the French victorious, they had moved only a few hundred yards from where they began, having obliterated a piece of earth larger than the city of Paris.

More than 300,000 families lost their sons in this battle of attrition have to come to terms with their loss, and nine villages had been blasted into oblivion, 'submerged in soldier's blood, crammed with dead bodies gnawed by rats', according to contemporary Abbot Thellier de Poncheville.

What they could not have known then, as they counted the cost, was the damage they had done to the land.

Stark:This is the site of a former munitions dump. Once it is cleared, there are plans to turn it into a solar power farm

The trenches: This would have been a wood just months before the battle began in February 1916

Destroyed: Nine villages were destroyed and never rebuilt, in memory of what had happened here. Now the roads and churches are marked by signposts, like this one in the former village of Bezonvaux

Cost: The ruined town and cathedral of Verdun after the Germans tried to take it in 1916

Secrets of the forest: There are other reminders of the war hidden in the forest, like this German bunker, in an area where they had a hospital, rail connections and a command post during the battle

Horrific: Both sides used poison gas to make gains in the Battle of Verdun. Left, a soldier in a gas mark, right, bodies in a trench

Remains: The trenches can still be made out by tourists visiting the woods today

The remains of the young men who fought valiantly for their countries were hidden in what once had been a peaceful idyll.

Then there were the chemical-packed weapons which exploded across the once green fields, lying on the ground. It is thought as many as 65 million shells may have been fired over the course of the battle, many of these filled with poisons.

The French immediately took the danger seriously: a year after the war's end, it bought 10,000 hectares of battleground, consigning the villages to history and allowing nature to take back the blighted land.

Officially, it was a Zone Rouge - an area in a crescent shape around Verdun, considered too dangerous to allow people to return in the immediate aftermath of the war.

Those who did venture onto the battlefield risked stepping on a shell meant to explode generations before. According toLe Monde, some 15 per cent of the shells shot during World War One failed to explode.

And they are still deadly - the sound of the poison liquids inside can still be heard.

The most recent fatalities came in 2007, when a live mine blew up as two workers tried to carry it to the munitions plant, where it would have been defused.

But attempts to clear the area of its dangerous bounty seemed doomed to failure.

Clearing the land of the detritus of the war in the worst affected areas is a 'near impossibility', Henri Belot, who was responsible for 'de-mining' the area, said a number of years ago.

Indeed, the entire forest would have to be destroyed, and at least a metre of soil dug away to find unaffected ground.

Explosive: These are just some of the shells which have been found in the ground around Verdun in the years since

Bravery: French soldiers run out onto the battlefield outside Verdun. They would eventually win, but would lose 163,000 fighters

Lethal: A bomb being exploded in the forest - during the battle this would have happened hundreds or thousands times a day

Burning: Verdun managed to survive the onslaught, but other places were less lucky

A study, published in 2007, claimed the levels of arsenic, used in the detonators, were between 1,000 and 10,000 times the level usually found in the ground.

It is so high, only a handful of plants are able to survive in some areas.

'It would be another disaster for the environment, and also for the finances of the state,' Belot said simply.

In 2008, it was decided to fence off the worst-affected area for good. Known as the Place-a-gaz, in the Spincourt Forest, it was the site where 200,000 unexploded chemical bombs were destroyed.

However, they have made some progress: swathes of land around the edge have been returned to the local population, and walking tours now show off the amazing variety of orchids and amphibians which have flourished on the pockmarked battlefield.

And there are now farmers making their living from the land - although every year their ploughs turn up more and more of the shells in the so-called 'iron harvest', which means it is not unusual to find piles of metal at the side of a field.

Discovered: Rusted rifles found in the ground around the French town of Verdun. People have been killed by the bombs left behind after the battle as recently as 2007