Lake Sandvatn has an area of 2,6 km². It is rather shallow and situated at 569 m above sea level. River Sanda empties into it from lake Alftavatn and river Ranga, its discharge, tributes to river Lagarfljot. River Ranga is among the best char and trout rivers of the East.

There are no road connections to the lake and the walking distance is rather long. The catch consists of large lake char. A long time ago, fries were released into the lake, and at the time none knew if there were any natural life in it.

The distance from the capital is about 671 km by the Whale Bay tunnel and 15 km from Egilsstadir.