BERLIN, May 21 (Xinhua)-- On Monday, more than 1,100 mills across Germany, historic ones and replicas, had their giant blades turned and grinders powered on to celebrate the 25th German Mills Day.

According to the organizer, German Society for Milling and Milling Conservation (DGM), the purpose of the festival is to direct public attention and interest to these technical monuments that had a history dating back to over 2,000 years ago.

On the German Mills Day, participating mills hosted various activities ranging from guided tours to sales of freshly grinded flour or extracted oil.

The Marzahner Bockwindmuehle, a wind mill built in 1993 as a replica of a 19th century mill in Berlin, is among the 1,100 mills that invited the public to see how they work and relish what they produce on this particular day.

Caroline sit with her six-year-old son on a stool mounted on the second floor of the mill, holding a paper bag stuffed with 750 gram of flour she just bought, teaching her son how the flour actually came about.

"I think it is very important for young children to learn about these technical traditions, and it is interesting to try this mill grinded flour, after all, it is not something you can buy every day," She told Xinhua.

Susanna and her husband from a town near Berlin took their 4-year-old and 2-year-old to visit the mill, because one of their children once saw a mill on a book and thought "it was cool". Susanna felt fortunate that some mills are still well preserved so that children could see them in real life.

Mario Lietz, a veteran police officer and now a volunteer instructor of the mill, gave instructions to visitors on how the wind mill functioned and differences of various grains. He told Xinhua that nowadays people only buy grain produces from supermarket, but it is important to show children and adults as well how did the produces turn from harvested grains to something people can put into their mouth.

Wolf, 82, said, "it is great to see the first machine of human history."