In Norse mythology, Élivágar (Old Norse: [ˈeːleˌwɑːɣɑz̠]; "Ice Waves") are rivers that existed in Ginnungagap at the beginning of the world. The Prose Edda relates:
The eleven rivers traditionally associated with the Élivágar include the Svöl, Gunnþrá, Fjörm, Fimbulþul, Slíðr, Hríð, Sylgr, Ylgr, Við, Leiptr and Gjöll (which flows closest to the gate of Hel and is spanned by the bridge Gjallarbrú), although many other additional rivers are mentioned by name in both Eddas.