Tunnsjøen


or is a lake in Røyrvik Municipality and Lierne Municipality in Trøndelag county, Norway. The lake lies just south of the large lake Limingen, and just west of the border with Sweden. It is above sea level and has a volume of. The deepest part of the lake is deep. It is the seventh largest lake in Norway.

Islands

The island or lies in the lake Tunnsjøen. The island's highest point is above sea level; which is higher than the lake. The peak is named Gudfjellet. This makes Gudfjelløya the highest island within a lake in Norway. It towers higher than the island of Monte Isola within Lake Iseo, in northern Italy. The island is located in the lake's central part. To the southwest of the island is the lake's second largest island:, also known as Litlfjelløya or . Its highest point is above the lake's water surface.