National Mills Weekend is observed in the United Kingdom every second weekend of May, specifically on the second Saturday and Sunday of the month. This annual festival is organized by the Wind and Watermills section of the Society for the Protection of Ancient Buildings (SPAB) and aims to highlight the importance of protecting, repairing, and using traditional mills. During this event, many preserved watermills and windmills, which are usually closed to the public, open their doors for visitors. Excursions are offered to provide insights into the history and workings of these mills. The official website of National Mills Weekend lists the mills that will be open to the public. In past celebrations, themes such as "Mills in Art" have been successfully incorporated into activities run by mill owners.