Fort IJmuiden was built between 1882 and 1890 to defend the sluices of the North Sea Canal that linked Amsterdam to the open sea. It had seven heavy guns, including five 24 cm guns in an armoured battery. This had been built by Gruson in Germany and was made of Hartguss, a kind of wrought iron. It provided good protection, but was quite expensive. In 1939 the guns were taken out of service. They were too old and no longer effective against the new armoured ships. During WW II the armoured battery was used by the German troops that occupied the fort. That's why the battery survived, making it an unique monument. Recently the battery has been restored. A German bunker built on top of the battery, which was partly demolished in the sixties, has been removed, giving the battery its original look. For a drawing an armoured battery of the same kind click here.