The Koch-bunker is a small German one-man bunker. The bunker was 1.60 meters high and the thickness of the concrete was 60 cm. The Koch-bunker in this image is located along the Drentsche Hoofdvaart canal and was part of the German Frieslandriegel defensive line.

The name "Koch-bunker" is said to come from the German Nazi Erich Koch (1896–1986), but the name could also have been derived from a "Kochtopf" (cooking pot) because of the shape of its top . The different parts of the bunker were manufactured in factories and assembled on site. More than 5,000 Koch-bunkers were deployed on the Western Front from 1944 .