WWI battlefields remain uninhabitable for 300-900 years

Because of the unrecovered human remains, chemical contamination, plus unexploded artillery shells, all lost in the soil which at the time was churned into mud by the sheer volume of artillery used – many thousands of shells per hour, carefully and deliberately “walked” in a creeping fashion across the entire landscape (see this map for an example of the coverage they could apply).

To this day, farmers tilling the fields that made up the Western Front still turn up artefacts from the war including entire field artillery shells in what is called the Iron Harvest.

The areas declared unusable are known as the Zone Rouge