When the windmills could no longer keep up with the rising population and shrinking polder ground, the Dutch built a steam-powered pumping station in 1869 — the Wisboomgemaal. It runs on diesel now, and is the main reason the mills are no longer strictly necessary. The building sits at the centre of the visitor area and houses the visitor centre, with a short film and a quiet exhibition on how the polder was reclaimed.
It is a fitting complement to the mills themselves: the human invention that finally made wind power obsolete, displayed in front of the row of mills it eventually retired.