Kamp Amersfoort National Monument

National Monument Kamp Amersfoort is a museum focusing on the 47,000 people who were imprisoned in Kamp Amersfoort during World War II. It was the longest operating concentration camp in the German-occupied Netherlands. By 2021, the underground museum was opened to include a permanent exhibition and an annually changing exhibition.

Source: Wikipedia — Kamp Amersfoort National Monument (CC BY-SA 4.0)