The name Zaan also refers to the district through which the river runs. The district (Dutch: Zaanstreek  is believed to be the world's first industrialized area. During the Dutch Golden Age in the 17th century, the Zaan district was dotted with windmills, which processed materials such as linseed, used in the paint industry, and agricultural products such as mustard seed and wood. By the mid-17th century, approximately 900 windmills could be found along the river, some of them still preserved in the Zaanse Schans. The Zaan district continues to be a heavily industrialized area with many factories, particularly around the city of Zaandam. A number of major Dutch companies, like Ahold and Verkade, were founded in the Zaan district.