Lake Selvallavatn has an area of 0,85 km² and is located 62 m above sea level. River Fossa enters it from the east and a few small brooks from the south.
The lake does not have any discharge on the surface. It abounds in brown trout and lake char (1-6 pounders). The surroundings of the lake are very beautiful and peaceful and it is possible to drive all the way up there.
The distance from the capital is about 198 km.