Ífingr
In Norse mythology, Ifing is a river that separates Asgard, the realm of the gods, from Jotunheim, the land of giants, according to stanza 16 of the poem Vafthrudnismal from the Poetic Edda:
John Lindow in Norse Mythology states in reference to Ifing that a river on which ice will never form is one that runs swiftly and therefore is extremely difficult to ford.
