Private property Oil mill De Os dates back to before 1663. This makes it one of the oldest industrial mills ever to have been built in the Zaan region. Until 1916, it was powered by wind, but then the cap, sails and gallery were removed. The internal workings of the mill remained intact, however. The dismantling of the mill in 1916 was an important moment in history. Between 1916 and 1931, it was powered by a diesel engine. This marked the transition from wind to other sources of power, a milestone in the history of the region’s mills. The occupant of the mill shed alongside De Os also manages the drainage mill De Hadel and the oil mill De Ooievaar. Extracting oil from seeds is done using large millstones. You can see these in action in the oil mills De Zoeker and De Bonte Hen.