Windmills are a milestone in the history of farming technology. They harness the power of the wind and convert it into rotation to power heavy grindstones - which in turn crush grains to produce flour. Back in the days when they were in use, windmills spared people hours of back-breaking work, though nowadays most of those that have survived are preserved as museums. This series of images recalls the strange and wonderful forms of these bygone buildings. Calvendo calendars are premium products - a bit more pricey than others but with added benefits: Our calendars always look beautiful on your wall because we produce them locally with premium paper and sophisticated spiral binding, ensuring easy turning of pages and flat hanging against the wall. A protective transparent plastic cover sheet provides added stability and each calendar comes in five languages. Treat yourself to a Calvendo calendar and you get something that looks better all year round.