Southern and part of Central France shares its eastern borders with Italy and Switzerland, not with Germany. As Switzerland remained neutral throughout the war and Italy began as neutral but joined the Allies in 1915, Southern France was largely spared from the destruction that occurred in Northern France.

The central border area near Switzerland is fairly mountainous compared to the North, due to the Vosges Mountains. However, fighting still occurred along that part of the border, especially during the opening stages of the war before the front line had fully stabilized.

Therefore, the largest battles on the Western Front mainly took place in the area of border that stretched from up near the sea in West Flanders, down to the area around Verdun. The land between was (fairly) flat, and very important - a German breakthrough could seriously threaten to both split the British and French forces in two and drive towards Paris. The Germans almost achieved this in both Fall 1914 and Spring 1918, but in both instances they were halted near the River Marne (giving name to the First and Second Battles of the Marne).