Why were the windmills at Kinderdijk built ?

                                 

Kinderdijk , in the Netherlands, is a village situated at the confluence of two rivers, the Lek and Noord. The dominating feature of the landscape of Kinderdijk is its windmills. The windmills were erected in the 1600's to drain the Alblasserwaard polders, which had suffered floods, since the 13th century.

Large canals were dug to get rid of the excess water in the polders. However, the drained soil started setting, while the level of the river rose due to the river's sand deposits. After a few centuries, an additional way to keep the polders dry was required.

                                

It was decided to built a series of windmills to drain the water into a reservoir from which it could be pumped out into the river. Nineteen windmills were built  and these have been beautifully preserved in a pristine condition.