#Fortification
Westwall near Kerkrade
On 9 October 1938, Hitler announced a new expansion of the Westwall. Previously, industrial cities such as Aachen and Saarbrücken had been left out of the defensive network, but he had changed his mind. A new line of defence around Aachen was immediately established. This part of the Westwall began at Herzogenrath near the Dutch border at Kerkrade, then passed in front of Aachen and joined up with the existing Westwall at Steckendorn. An estimated 750 bunkers and many kilometres of tank barriers were located in the new section.
The Westwall (also known by the Allies as the Siegfried Line) was a German defence line that was built between 1936 and 1945. The more than 600-kilometre-long line stretched from Cleves, on the Dutch border, to Switzerland. The extensive defence system was a chain of tank barriers (dragon's teeth), bunkers, machine-gun nests and barbed-wire fences that were intended to stop the Allied troops at the German border.
From the autumn of 1944 onwards, the Westwall only proved its worth in some places, such as the Hürtgenwald south of Aachen, where the German defenders blocked the American advance for months. Aachen itself had already been taken by the Americans on 21 October 1944. It was the first city on German territory to fall into Allied hands.