There are many tails told About this recognizeable rock. How it got the way it is will however be a mystery forever.
If you believe an old tail the rock is there to remember those who drowned an accident with a horse carriage in the 18th hundreds. There is also a tail involving guests of a wedding, however that is probably an mistake and that Story connects to the wedding cross at the Wolfgangsee. There is another tail About a man who almost drowned but could save himself on the rock.
In a paper (Dillinger's travel News paper) from the year 1908 they are advertisements for the hotel Kreuzstein, which was built in 1906. There isn't anything to read About the rock though.
Old People could tell of the emergence of the Stone in the water if they should prepare for famine.