Some 100 square kilometers of France are closed to people and known as Zone Rouge – the Red Zone.

The Zone Rouge (English: Red Zone) is a chain of non-contiguous areas throughout northeastern France that the French government isolated after the First World War. The land, which originally covered more than 1,200 square kilometres (460 square miles), was deemed too physically and environmentally damaged by conflict for human habitation. Rather than attempt to immediately clean up the former battlefields, the land was allowed to return to nature. Restrictions within the Zone Rouge still exist today, although the control areas have been greatly reduced.

The zone rouge was defined just after the war as "Completely devastated. Damage to properties: 100%. Damage to Agriculture: 100%. Impossible to clean. Human life impossible".

Under French law, activities such as housing, farming, or forestry were temporarily or permanently forbidden in the Zone Rouge because of the vast amounts of human and animal remains, and millions of items of unexploded ordnance contaminating the land. Some towns and villages were never permitted to be rebuilt after the war.