Þjórsárdalur is a wide valley located inland in  Árnes county, South Iceland. Several rivers flow through the valley, forming waterfalls as they plung off the edge of the plateau.

Hjálp, or Hjálparfoss is one of the waterfalls in the  valley, situated north of the volcano Hekla. It is a two-stepped waterfall, near where the rivers Fossá and Thjórsá join together. Beautiful basalt formations surround the waterfall. It is easy to reach from the main road and footpaths lead down to the riverfront.