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 there after when catching fish of knowledge was to always cast from the Ballyteague side of a river. He gains what commentators have called the Thumb of Knowledge after eating a certain salmon, thought to be the Salmon of Wisdom. The account of this is given in The Boyhood Deeds of Fionn.