Historically, windmills in Holland served many purposes. The most important probably was pumping water out of the lowlands and back into the rivers beyond the dikes so that the land could be farmed. In the fourteenth century, hollow-post mills were used to drive scoop wheels to drain the wetlands. The Molen de Roos in Delft began its life as a hollow-post type and was later rebuilt with a higher stone construction in the eighteenth century. Today it has been restored and is open for viewing. In Amsterdam, you can see the Molen de Otter, the only wind-powered sawmill left in operation.
The windmills today
There are over 1000 windmills in Holland. Some are still being used for drainage, such as one or two of the nineteen in Kinderdijk. The Molen de Otter, still in operation in Amsterdam, is also used for drainage. The Molen de Valk in Leiden has been restored and now grinds grain once again. It is also a museum, a witness to the history of windmills in the area. The few mills that still turn are on the verge of losing power: with buildings around them getting higher, they can no longer catch the wind as they used to do.