Fort Spijkerboor: A Defensive Fort in the Stelling van Amsterdam
Site at a Glance
- Rating
- 4.3
- Popularity
- Low
- Country
- Netherlands
- Primary era
- Modern
- External website
- Open
- Eras represented
- Modern
- Civilizations
- Dutch
- Site type
- Military
- Remains
- Fort
On this page13 sections
History
Fort Spijkerboor is a Dutch military fort near Spijkerboor in the Netherlands, built between 1889 and 1913 as part of the Stelling van Amsterdam, a defensive ring of forts, flooded zones, dikes, and other military works around Amsterdam. It defended the Northern Front by controlling routes along the western Beemster ring canal, together with the embankments and roads beside it.
Construction and military role
The fort stands beside the Westdijk of the Beemster, at a strategically important meeting point of the Noordhollandsch Kanaal and the ring canals of the Beemster and Starnmeer polders. A polder is low-lying land enclosed by dikes and maintained through controlled drainage. The position lay between Krommenie, Castricum, Alkmaar, and Purmerend, where roads, embankments, and waterways could provide access through land intended for flooding during a military emergency.
Fort Spijkerboor was among the most modern and heavily armed forts in the defensive ring when it was constructed. It combined the work of an artillery fort with that of an infantry fort, allowing it to support long-range fire while also defending the surrounding approaches with ground troops. The fort was mobilized during the First World War, when about 300 soldiers were stationed there.
Prison and wartime use
At different times, the fort became a prison for conscientious objectors, men who refused military service on moral or religious grounds. The writer Herman de Man was imprisoned there in 1918 for refusing military service, as was Herman Groenendaal.
From 1939 until May 1940, German and English pilots were held at Fort Spijkerboor. During the May Days of 1940, several prominent members of the Dutch National Socialist Movement were detained there, including Kees van Geelkerken. The movement was a Dutch fascist organization that collaborated with Nazi Germany during the Second World War.
Between 1942 and May 1944, the fort served as an emergency prison for black-market traders and men who refused compulsory service in the Dutch Labour Service. After the war, from May 1945 to March 1946, it held political delinquents, including members of the Dutch National Socialist Movement and artists who had worked for the wartime Culture Chamber.
From 1946 to 1947, the fort became a camp for men who refused military service in the Dutch East Indies. They were willing to fight for the Netherlands but opposed serving as colonial occupiers. The last prisoner left on 18 June 1951. Many wall paintings in the poterne, a protected passage within a fort, date from the prison period, particularly the years shortly after the Second World War.
Later changes and conservation
From 1970 to 1975, the Bergsma and Bos families lived in the former barracks. In 1975, the Ministry of Defence sold the fort to the Dienst Domeinen, the government agency responsible for state property. The Prijs family served as fort keepers for many years. Dienst Domeinen sold the fort to Staatsbosbeheer, the Dutch state forestry and nature-management agency, in 1992.
The fort is now leased by the Vereniging Natuurmonumenten, a Dutch nature-conservation organization, which manages the fortifications and surrounding nature area. The restored complex is used as a museum and for beer storage. A radio beacon for aviation operated at the fort from 1952 to 1990; air traffic is now assisted by a VHF omnidirectional range station about one kilometre east of the site. The poplar woodland south of the fort is gradually being transformed into more varied deciduous woodland.
Remains
Fort Spijkerboor is a concrete, two-storey fortification whose bombproof buildings stand inside a moat, with surrounding fortifications and a glacis. A glacis is a gently sloping earthwork outside a fort that exposed approaching forces to defensive fire while limiting their cover. The buildings, defensive works, former barracks, and surrounding landscape together form the surviving fort complex.
Concrete fortification and armament
Two-storey fort and armoured turret
The fort’s two-storey arrangement is almost unique within the Stelling van Amsterdam. Fort bij Hoofddorp also has two storeys, while Fort bij Abcoude is an older brick fort built according to the standards of the Nieuwe Hollandse Waterlinie. Fort Spijkerboor’s concrete structure was equipped with an armoured turret containing a double-barrelled 10.5-centimetre cannon, reflecting its combined artillery and infantry role.
Moat, fortifications, and glacis
The bombproof buildings are enclosed by a moat and linked to the wider defensive system through the surrounding fortifications and earth-covered glacis. These elements formed the physical framework for defending the canal, embankments, roads, and other access routes around the western Beemster. The fort complex and its outer works are now managed within a nature area.
Interior spaces and later installations
Poterne wall paintings
The poterne contains several visible wall paintings made while the fort was used as a prison. Most were produced shortly after the Second World War, when National Socialists and, from 1947, men opposed to fighting against the Indonesian independence movement were detained there. The paintings preserve part of the fort’s later history within its protected passage.
Kitchen and former barracks
A kitchen has been installed in the restored fort with furnishings and equipment from Fort bij Marken-Binnen. The former barracks remain part of the complex. They served as housing for the Bergsma and Bos families between 1970 and 1975, after the fort’s principal military and prison functions had ended.
Aviation beacon
The fort also retains the history of its post-war aviation role. A radio beacon operated there from 1952 to 1990, adding a twentieth-century communications function to the earlier military uses of the site.
Surrounding nature area
The fortifications and landscape are managed together as a nature area. Marsh harriers, reed warblers, linnets, sedge warblers, little owls, and kestrels occur there, while barbastelle bats spend the winter inside the fort. The gradual replacement of poplar woodland south of the fort with more varied deciduous woodland forms part of the area’s continuing management.
