Is this to ward off evil spirits?

[Downtherefordancing]

This is a (rather large) garden we walk past most days. The house has new owners who have put a rock on every fence post. Does anyone know if this is for any reason?

Or maybe they just needed somewhere to put their collection of rocks?

Could be to stop water getting into the end grain of the post and rotting it.

They think it looks nice 🤷🏻‍♀️

I think @VeniVidiWeeWee has got it in one.

Thanks venividiweewee - that makes sense 😊