Lunenburg Castle, locally known as Kasteel Lunenburg, lies in the village of Langbroek, in the province of Utrecht in the Netherlands.
It is unknown when Lunenburg Castle was first built. The name Lunenburg is first mentioned in 1339. The builders of Lunenburg Castle are most probably the Van Zijl family.
The tower house itself was first mentioned in 1400. In 1402 it was given as a fief to Ghijsbrecht van Lockhorst. At that time the castle consisted of the tower house with several outbuildings and lands for agricultural purposes.
The descendants of Van Lockhorst owned the castle until 1563 when it had to be sold to Maarten Schipperius. Schipperius in his turn sold the castle to the mayor of Utrecht; Godard Boll, in 1580.
In 1680 Lunenburg Castle was enlarged with residential wings and stables which were built against the medieval tower house. In 1860 the owner at that time, a member of the Van Swinderen family, rebuilt the castle. This meant that the 17th century additions were torn down and that almost the entire moat was filled in. The medieval tower house was then incorporated in a new large mansion which rendered the tower almost invisible. After this the castle was rented out and sold several times.
Between 1925 and 1931 the castle was owned by Mr. Ernest Reinier van Eibergen Santhagens who provided the castle with modern comfort.
On 13 May 1940 Lunenburg Castle was searched by German troops for hidden arms and ammunition, causing much damage in the process. In 1944 the Germans had parked military vehicles under the large trees on the grounds of Lunenburg Castle. This led to a useless bombardement of the castle by Allied forces, because the vehicles had already been removed, which left the castle as an uninhabitable ruin.
Between 1968 and 1970 Lunenburg Castle was rebuilt after its appearance before 1800. This led to the situation we see today. At present the castle is owned by the Fentener van Vlissingen family.
The present tower is 15,5 meters high, is almost square with 8,4 by 9,3 meters and has a wall thickness of 1,2 meters.