Lake Svartarvatn has an area of 1,9 km². It is situated 395 m above sea level east of the southernmost part of the valley Bardardalur. Its catchment area is a few brooks and it is discharged by river Svarta, which tributes to river Sudura.
It is possible to rent boats on the lake, but they have to be reserved in advance. The catch consists of lake char. Ice fishing during winter. There is no road around the lake and its circumference is about 2 km. Late in the 19th century the farmer at Svartarkot released lake char from lake Myvatn into the lake. He also poured hatched lake char roes into it and was thus the first to experiment with fish rearing in Iceland. The distance from the capital is about 458 km via Akureyri by the Whale Bay tunnel. A fine hiking trail is from Svartarkot to Herdubreidarlindir.