Bárðardalur, the valley opening between Ljósavatnsskarð pass and Goðafoss and reaching up onto the moors, one of the longest inhabited valleys in Iceland, but rather narrow and shallow.

Basalt mountains up to 750 m on the west, Fljótsheiði moors, (528 m) on the east.

The river Skjálf­anda­fljót flows through the valley over the Bárðardalshraun lava field that probably came all the way from Trölladyngja in Ódáðahraun north of Vatna­jökull more than 7,000 years ago.

The valley is dry, mostly grassy, but with some soil erosion on the eastern side. Bushes on the western slopes. Few farms but good sheep pastures.