Less than well known, the Aldeyjarfoss waterfall is situated in the Highlands of Iceland at the northern part of the Sprengisandur Highland Road. The river Skjálfandafljót drops here from a height of 20m. The basalt belongs to a lava field called Frambruni or Suðurárhraun, hraun being the Icelandic word for lava. --Excerpt from Wikipedia