The fields around the battlefield of Ypres, the site of four years of bloodshed during World War I, are littered with hidden trenches, bunkers and dugouts that are being excavated by archaeologists. But the expansion of an industrial park, combined with the city of Ypres' rapid expansion, threatens to destroy kilometers of hidden history.  Nina-Maria Potts reports for VOA.

The exact number of lives lost in World War I through the horror of trench warfare and the world's first poison gas attacks is uncertain, though some estimates range up to more than 30 million dead, wounded or missing.

Around the Flemish town of Ypres, hundreds of thousands of men died. The town was rebuilt, and many of those soldiers are still here, or buried where they fell.

Ninety years later, industrial development threatens to swallow up the remains of the war.

Now an effort is underway to protect the town's World War I heritage and its important economic role through tourism.

Piet Chiemens at Flanders Fields Museum is searching for a way to protect that heritage from development. "We have to know exactly where the boundaries are going to be - of farming land, new developments as far as industry goes, or building in general," said Chiemens, "because the very small area we are talking of, it is just that semi-circle standing around the town of Ypres itself, is of such historic interest, that we should try and defend it with all means."

In nearby Zarren, a team of archaeologists has conducted trial excavations of the industrial zone and are analyzing artifacts brought to this depot.

Chief archaeologist Marc De Wilders says the war often lies intact beneath the first 60 centimeters of soil. "It was immediately very clear that the heritage, what was left of that war, what was left, was very large, so the conclusion was that if one was to build something over there, there would be an enormous destruction," he said.

Historians explain Ypres' rapid industrial development by pointing to the psychological impact of war.

Piet Chiemens says the inhabitants of Ypres were especially keen to move on with their lives, having lost so much.

"The whole of the region here had an immense blow with that war, and was thrown back miles [kilometers] in comparison to other regions that didn't have that experience," added Chiemens, "and every single road that was built, every single factory that went up, was actually the final victory over that war."

Belgium's high population density and pressure from industrial development make the work of amateur archaeologists like " the Diggers" invaluable.

Digger Patrick Wanzeele says the Yorkshire trench was discovered in the nick of time. "The whole battlefield is now under the industrial zone,” Wanzeele said. “Twenty years ago, you could see no buildings here, just shells here, here, everywhere - now it's too late. I am glad now here, there is a little monument," said Wanzeele.

With the 100-year anniversary approaching in 2014, interest in World War I continues to grow, and the economic benefit brought by 330,000 visitors to Ypres last year has given the modern defenders of these battlefields added ammunition.