The Mill De Slokop in Spaarndam is a traditional windmill with low sails. The word ’Slokop’ is Dutch for ’one that is always thirsty’. The mill is an eight-cornered polder mill. It was built in 1877. Windmills were often used to drain bodies of water to form polders – areas of land separated artificially (by pumps, dikes, and canals) from natural bodies of water. The mill is no longer operational.