Sultartangi, a former isthums at the crossing of the rivers Tungnaá and Þjórsá. A 6 km wide dam has been constructed there and given the name Sultartangastífla. Sultartangastífla was built there to provide a reservoir for the Búrfellsvirkjun Power Statation. A tunnel goes out of the reservoir to the south–west through Sandfell to the Sultartangi Power Plant (120 MW), inaugurated in October 1999. The tunnel is 12 m high and 3,4 km long.