A so called “Kugelmühle” (polishing rough stones into perfect spheres) in the village of Fürstenbrunn in <a href="https://en.wikipedia.org/wiki/Salzburg_(state)" class="extiw" title="en:Salzburg (state)">Salzburg</a>
<a href="//commons.wikimedia.org/wiki/User:Rudolf_Sch%C3%BCrer" title="User:Rudolf Schürer">Rudolf Schürer</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>