Based on a folk Polish fairy tale Ancient, a charmed royal lived in the dungeons of Ostrog Castle, turned into a golden duck. They said that she could make the one who managed to find her rich. Many daredevils tried to do this. Once a young shoemaker on the night of Ivan Kupala went to the dungeon of the castle. Happiness smiled at him, and he met a golden duck who promised him wealth. She set only one condition: