The river was originally a side arm of the IJ bay. It runs about 10 kilometers through the municipality of Zaanstad ("Zaan City") north of Amsterdam, from West-Knollendam in the north to Zaandam in the south, where it empties into the IJ.
The river runs past the Zaanse Schans, a village with historic windmills and houses. It is one of the most popular tourist attractions in the Netherlands.
The district (Zaanstreek) is believed to be the world's first industrialized area. During the Dutch Golden Age in the 17th century, the Zaan district became dotted with windmills. By the mid-17th century, some 900 windmills could be found along the river. Today 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.
French impressionist painter Claude Monet stayed in Zaandam in the summer of 1871 and produced a series of 24 paintings of the Zaan district, writing to his friend Camille Pissarro that, "there is enough here to paint for an entire lifetime. Monet returned to the Zaan district to paint during visits to the Netherlands in following years.