southwest of Ouderkerk (Amsteldijk-Zuid 54-55, municipality of Amstelveen) was founded in 1719 by Nicolaas Calckoen and in 1742 taken over by Nicolaes and Hendrik van Hoorn. In 1782 an explosion followed. Shortly thereafter, the long L-shaped building on the dyke with a bell-gable above the entrance and on the lintel dates the text: 3. Next to it is a cylinder mill with grinder for the black gunpowder.
In 1843 the factory became part of the United Buskruidfabrikatie. From 1885 to 1922 it belonged to 'The Joint Bus Spice Makers of North Holland, Utrecht and Zeeland' (factories in Muiden and Ouderkerk) and from 1922 to 1991 to the N.V. Nederlandsche Sprinklerfactories. Striking is the water tower from 1895, built according to J.F. Riveter and B.J. Ouëndag with a round brick substructure and an eight-sided wooden superstructure containing the high reservoir. Against the tower is the laboratory (1910, extended 1925 and 1955). In addition, a salpet warehouse (1896), a salt and cotton warehouse (1903), workshops and other warehouses are located on the forecourt. In 1998-2004 the complex was renovated for housing and small businesses. There are still a few buildings in the backyard for the earlier production of hazardous materials, such as the shooting cotton factory (1895) and the nitroglycerine-cum dynamite factory (1907-'18). At the gunpowder factory the one-storey workers 'houses Amsteldijk-Zuid 23-40 (1905, B.J. Ouëndag) and the traditionalist administrators' houses Amsteldijk-Zuid 59-62 (circa 1940) belonged.
