I've taken a few weeks to spot it, but the National Geographic photo of
the day for Nov 25, 2003 was of
Windmills in La Mancha
I don't actually think the photo, shot by James P. Blair in 1981, is all
that good - it's got no particular focus, and would benefit from being
cropped to keep just the bottom half, making it into a panoramic shot.
You can download the image in a large enough size to use as a desktop background.
Photo of the day - La Mancha