Lake Midhusavatn, a bit farther west than Budir, has an area of about 1,8 km², its greatest depth is 2 m and it is situated 1 m above mean sea level.
A long natural reef serves as a barrier between the lake and the sea. Its discharge runs through Grafaros. The catch consists mainly of sea trout. The lake is beautifully situated.
The distance from the capital is 190 km by the Whale Bay tunnel and 116 km from Borgarnes.