Finn MacCool and the Giant’s Causeway

Northern Ireland as the land of fairies, leprechauns, storytellers, saints and scholars, giants, beautiful scenery, churches, epic battles, and Norman castles. Ireland is a land of tall tales and ancient myth, and the legend of Finn MacCool and the Giant’s Causeway is one of the most widely spoken.
Thumb of Knowledge
Fionn was a keen hunter and often hunted with Na Fianna on the hill of Allen in County Kildare, it is believed by many in the area that Fionn originally caught the Salmon of Knowledge in the River Slate that flows through Ballyteague. The secret to his success thereafter when catching "fish of knowledge" was to always cast from the Ballyteague side of a river. He gained what commentators have called the "Thumb of Knowledge"[c] after eating a certain salmon, thought to be the Salmon of Wisdom. The account of this is given in The Boyhood Deeds of Fionn