I found those stones at the Baltic Sea while walking along the Brodtener Ufer steep coast (click the link because it’s such a nice place). Before that, I’ve never known that this is an actual activity. It’s called rock balancing as I have learned later. This place was full of balanced rocks. I wasn’t sure why they were all in one place. I still have other photos. Maybe it’s where some people meet to do this activity or someone went nuts and couldn’t stop balancing stones (lol). Maybe it was a Monk, we will never know. All I know is that I’ve done similar exercises in the past, for example when I tried to balance cards or coins.