consider this option from Brilliant Maps:
Parts of France Where Nobody Lives Within 1km
Map crated by @matamix
The map above shows where nobody in France lives, based on 1km2 squares. In total, 31.7% of metropolitan France is uninhabited.... MORE
Which is actually pretty remarkable considering the number for the United States is 47%, despite the fact that France is almost 4X more densely populated than the United States (123 people per km2 vs 34 people km2)...
That's really kind of amazing.