What you saw may have been a windmill.
Windmills look like giant fans.
They have lots of blades on a horizontal axis and soar high above. Windmills may not look like much, but they have been very useful to farmers and ranchers. Windmills are machines operated by windpower. Windmills first began in the A.D. 600's in Persia, present-day Iran. People then used them to grind grain.