On 13 December 1947, Queen Wilhelmina lay a wreath at the National Monument on Dam Square. Representatives of the Dutch provinces placed urns inside the monument.
The urns contained soil from all Dutch provinces and from specific places. Places where people had been shot. From the Grebbeberg, where heavy fighting had taken place in May 1940, and from Walcheren, where the Allied army had landed. The soil from the province of Noord-Brabant was mixed with the ashes of cremated prisoners from camp Vught. It made the National Monument a symbolic grave for all those who had given their lives for their country.