The Kottmarsdorf post mill from 1843 was in operation for 100 years and is now maintained by the municipality of Kottmar and the Kottmarsdorf Nature and Local History Friends Association. It is functional and you can visit it. On special occasions, such as Mill Day on Whit Monday, the traditional "show turning" is carried out, in which you can even help.
I highly recommend the Müllerstübchen. The service is super friendly. Above all, I was pleasantly surprised that there are still restaurants in Upper Lusatia that offer snacks. Here, Debrecen sausage with bread. Unfortunately, that's the exception these days.