Kogaionon was the holy mountain of the Geto-Dacians, the place where Zalmoxis stayed in an underground cave for three years. After his disappearance into Kogaionon, he was considered dead by the Getae but after three years he resurrected and showed himself to the people, who became convinced by his holy preaching when he emerged from Kogaionon. Strabo claims that a river with the same name flowed in the vicinity.