Green Light for the Preservation of Oud-Wassenaar Castle, a Top 100 National Historic Landmark

The castle stood vacant for years and fell into visible disrepair. This put the building, its exceptionally well-preserved interior, and the site’s historical significance at risk. Oud-Wassenaar Castle is one of the Top 100 monuments in the Netherlands; it is a defining landmark of Wassenaar and serves as a link between country estate culture, international diplomacy, and local history.

At the request of the province and the municipality, Monumentenbezit assumed temporary management of the building in early 2025. During that period, further deterioration was prevented: the building was made wind- and watertight, the indoor climate was stabilized, and conservators continued to document its heritage values in Map. Work was also carried out on a comprehensive plan for acquisition, restoration, sustainability improvements, repurposing, and semi-public access.

“The preservation of Oud-Wassenaar Castle is exactly the kind of challenge for which governments need to work together. The Administrative Agreements on Cultural Heritage stipulate that the Health monuments is a shared responsibility of the national government, provinces, and municipalities. Heritage impacts spatial quality, sustainability, and quality of life. Especially in the case of complex restorations, where capacity is scarce and the task is daunting, we must coordinate our roles and tools. “Oud-Wassenaar Castle demonstrates how that collaboration can take shape in practice,” said Meindert Stolk, a member of the Provincial Executive of South Holland.

“This is a good example of public-private cooperation. The municipality, the province, Monumentenbezit, the National Restoration Fund, and concerned local residents are all contributing to the preservation of an important monument for Wassenaar. In doing so, we are putting the recently concluded administrative agreement on cultural heritage into practice,” said Alderman Frigge of the Municipality of Wassenaar.

Made possible together

The total project—encompassing the purchase, restoration, and repurposing of the building—requires an investment of approximately 12 million euros. This project can only succeed through collaboration. The National Restoration Fund, the province of South Holland, and the municipality of Wassenaar are working together to make a financially viable plan possible. Local residents have also actively contributed their ideas and provided financial support. This clearly demonstrates the strong support in the immediate vicinity.

Through this joint effort, the castle can be placed in the hands of a professional owner who prioritizes the long-term interests of the historic monument. The proposed repurposing should restore the building’s significance, while respecting its heritage values and the tranquility of the surrounding area.

“This project was complex on every front: the financing, the restoration, the repurposing, and the tight timeline within which clarity had to be achieved. That is precisely why it is so remarkable that so many parties have taken responsibility. With this step, we can halt the deterioration and work toward a careful restoration and a fitting future for a castle that is of great significance to Wassenaar and to the Netherlands,” said Mark van den Bos, director of Monumentenbezit.

Monumentenbezit would like to express its sincere gratitude to the local residents for their involvement, ideas, and financial contributions, as well as to the National Restoration Fund, the province of South Holland, the municipality of Wassenaar, and the Oud-Wassenaar Castle Monument Foundation. Without their trust and dedication, this step would not have been possible.