After the Dutch neutrality was violated several times, like the sinking of several Dutch ships by German submarines, the Germans feared that the Dutch goverment would end the neutrality and choose the Allied side. At the same time they were afraid that the Allies could also violate the Dutch neutrality to outpass the German defenses. In both cases the first goal for the Allies would be the port of Antwerp. To protect the port the Germans started the construction of a new defence line in 1917. This line followed the outer line of forts. Here an observation post. It is one of the few that still has its armoured plate.