IJmuiden is the entrance to the harbour of Amsterdam. Besides that it is an important harbour and industrial area itself. The big locks in the Northsea canal, the steel factories on the northside of the canal and the presence of a Schnellboot base were of great strategic value. This is why a big effort was made by the Germans to defend this position. During the war it even got the Festung status. The Kernwerk was located on an island in the entrance of the canal around an old Dutch coastal fortress. On each side of the canal a naval coastal battery was erected and the Marine Flak positioned four heavy AA batteries in the Festung. A powerful Landfront supported by dragon teeth, anti-tank walls and ditches surrounded the area. Furthermore there were several fortified headquarters for different staffs, a fortified Mammutradar position and logistical sites.
Nowadays there is still a lot to see in IJmuiden. Highlights are, by far, the Kernwerk, which, although demolished for the greater part, still delivers the very rare intact 644, the Marine Seeziel Batterie 'Heerenduin' and the Marine Flak Batterie 'Olmen' which both lie on the southside in the dunes. Both are examples of very complete Ständige batteries. Near the two batteries you can find, in the harbour, the huge S-Boot bunker. South of the batteries begins the Landfront with an impressive Panzermauer and Höckerlinie. Here you can also find one of the two remaining Walzkörpersperre beautifully preserved near a 676 integrated in the same wall. The battalion headquarters for the southern forces can be visited in Driehuis near Velsen.
On the northside most of the bunkers were demolished due to industrial extension. Only in the dunes of Wijk aan Zee there are some remnants of the Festung. Highlights here are the Marine Seeziel Batterie 'Wijk' with an interesting Leitstand with steel turrets (M 120/473a). The Mammutbunker V 143 was recently dug up by a local bunker association. It is not far from the battery. An M 151 lies nearby. This is just a rough overview of what is left. There are still a lot of seperate and covered bunkers.
Ceiling of the Mg-turret on the Kernwerk