Tulip-shaped basalt columns near "Aldeyarfoss" (translated as the Old man's Waterfall), in the desolate "Sprengisandur" area. Basalt columns are formed as shrink cracks when lava is cooling down slowly.

The Sprengisandur is a so called outwash plain or sandur. It is created by sediment and debris, deposited or "washed out" by meltwater streams running from the glaciers "Vatnajökull" and "Höfsjökull".

The tight, winding gravel road over the "Sprengisandur" usually opens in the first week of July and remains open until September. In the rest of the year, the road is closed because a snowcover makes it impossible to drive on it.