The Fort near Spijkerboor is located in the southwest corner of the Beemster Polder. It is the most northern fort of the Defence Line of Amsterdam and also the biggest one.
When it opened in 1913, more than 300 soldiers were stationed in the fortress. Although this defensive structure remained in the possession of the army until 1975, it has been mainly used as a prison over the years. The conservation goal of the Fort near Spijkerboor is to highlight the traces of its use throughout the years. It presents a historical perspective, not only of a military object but also of important events in Dutch 20th century history: the flood disaster of 1916, the World Wars, the East Indies Crisis and the Cold War.