Quest \"the House of God\" - how to find the devil's skull? (Kingdom Come: Deliverance)

In General, the quest the House of God, where the monastery is building.. someone on Bosko dropped the stone, you need to find supposedly the devil's skull, all over the place, there is a piece of terrain a little but I can't find the skull, out of principle I would like to do it. Please tell me if someone has already found.