The defences consisted of over 15,000 strong points including coastal batteries, emplacements and concrete pill boxes supplemented by obstacles, minefields and barbed wire. The defences were organised into eight commands, Wehrmacht Netherlands Command controlling the defences in Holland.
The port of IJmuiden not only served as the port and entrance for Amsterdam, it was also a fast torpedo boat base. To protect the port, coast batteries, air defence batteries, as well as infantry positions were built together with a series of command centres.
In the middle of the harbour at IJmuiden on a small island the Kernwerk Fort is located. The casemates housed 2 x 15cm, 1 x 9.4 cm guns, an airdefence gun, as well as machine gun emplacements.
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| Kernwerk Fort Eiland IJmuiden harbour |
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| Kernwerk Fort Eiland |
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| Kernwerk Fort Eiland |
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| Kernwerk Fort Eiland Casemates dominating sea entrance |
To the south of the harbour lies the Seeziel Batterie Heerenduin
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| Seeziel Batterie Heerenduin |
