A Post Mill is a type of windmill that has a rotating structure mounted on a single vertical post. This design allows the entire mill to be turned to face the wind, optimizing its efficiency in harnessing wind energy. Post mills were commonly used in Europe from the 12th century onward, particularly in countries like England and the Netherlands. The main components of a post mill include the body, which houses the milling machinery, and the sails that catch the wind. The miller can adjust the position of the mill by turning it around the post, making it a practical solution for varying wind directions. Post mills played a significant role in agricultural societies by grinding grain into flour.