Worldwide, windmills are often closely associated with the Netherlands. This relation can be traced back to the 17th century during which The Netherlands was going through an economical and cultural boom. During this era, windmills were vital for converting lakes and polder ditches into fertile land. For centuries windmills were the primary source of power in Holland.
In fact, about a century ago there were approximately 10,000 functional windmills and today there are still more than 1,000 mills, the majority of them located in Zuid Holland. Kinderdijk is the most famous place for windmills in Holland. The windmills are very well preserved and fully operational. In 1997 the Kinderdijk mills were placed on the World Heritage List of UNESCO. On Saturdays, during July and August all the windmills are set in motion.