This was filmed at La Ciotat, on the southern coast of France. This region actually survived WWI relatively unscathed. It did see a bit more action in 1944. But the war would have been a major event in these people's lives, even if the location wasn't directly in the middle of it.
The town did not see any action but, as all towns in France, all fit men were sent to the front lines, and many never came back, as illustrated by the monuments listing the deads of WWI and WWII in all French towns and villages.