The Atlantikwall was built during the occupation of Europe by the German Nazi regime, between 1941-1945.
The wall that had to resist allied attacks on fortress Europe, ran from the border between Norway and Russia over 6200 km to the border between France and Spain. Bunkers are part of the military landscape. Field fortifications, like foxholes, trenches, anti-tank ditches, etc. are also part of that system and can still be traced.