Wind power has been used for centuries to grind grain, pump water, operate machinery, and more recently to produce electricity.
There are many variations of windmills around the world, and most of us have seen them in various forms.
This thread is a call to post your favorite windmill photos to share. They don't have to be great shots, just shots with windmills in them.
I will start this one with a photo of a pair of modern power generating windmills that are part of a wind farm in Rio Vista, CA, USA.