The primordial frozen rivers whose ice gave rise to the first giant Ymir.

The Élivágar, the ice-laden rivers, flowed from Niflheimr's spring Hvergelmir and ran southward into Ginnungagap. Their venom-laden ice congealed into a primordial substance that engendered the first giant Ymir and the cow Auðhumla.

The encounter between the icy venom from the north and heat from Múspellsheimr in the south created the cosmic tension from which life and the world arose. The ice of the Élivágar thus forms the foundation of the entire Norse creation narrative.

Attestations

Gylfaginning 5
Snorri explains the role of the Élivágar in the world's creation.