The card shows a view from the village of Bourtange , which today has a population of around 430. The village is best known for Fort Bourtange , a star-shaped fortress built under the orders of William the Silent and completed in 1593. Its strategic purpose was to control the only road linking Germany with the city of Groningen , which at the time was held by Spain during the Eighty Years' War . The fort saw its final battle in 1672 and remained part of the Dutch defensive network along the German border until 1851. That year it was decommissioned and gradually developed into a village. Today, Fort Bourtange has been carefully restored and operates as a historical museum.