According to the saga, Lake Vanern was formed by the Goddess Gefijon. She was promised as much land as she could plow up in one night, so she turned her sons into steers and plowed the area of the present Lake Vanern. She removed the clods and piled them off the coast.
These became the Danish island of Seeland; and, as the legend has it, she then filled the open basin with water to create Lake Vanern.
Vanern is Sweden’s largest lake, and with an area of 5,600 square kilometers, nearly three times the size of Lake Vattern located 40 kilometers farther east. Reaching depths up to 92 meters, the lake was the inland part of a long fjord stretching from Gothenburg to far beyond Karlstad after the last Ice Age. Due to the land mass rising after the Ice Age, the connection to the sea dried up leaving the lake with thousands of skerry islands.
Lake Vanern is surrounded by four regions: Varmland lies to the north, Narke, to the northeast, nearly extends to the sea, Dalsland lies between the lake and the Norwegian border, and Vastergotland encompasses the area to the south and east. Five major roads circumvent the lake forming a ring.