Located directly upstream from Hraunfossar, the two waterfalls flow out of the Hallmundarhraun lava field.

Many Icelandic folk tales have been associated with Barnafoss, the most famous being about two boys from a nearby farm, Hraunsás.

The boys were supposed to stay at home, but as they grew bored they decided to follow their parents.

Another waterfall, Barnafoss, is on the river Skjálfandafljót near the abandoned farm Barnafell in Ljósavatn County.

Flocks of sheep were driven over that bridge to graze on Þingey, the island between the two branches of the river.