Hi! this question has two parts. Both sides dug massive lines of trenches and moved an incredible amount of earth during the war. So, when the war finally ended, who filled in all those trenches? Was it the property owner's responsibility? How long did it take to put the earth back where it belonged? Second, I assume some trenches were just abandoned as-is for decades. Were there cases of French soldiers in World War Two simply using old World War One trenches they came across to defend their country again in 1940?