Covering an area of 36.9 km², and with an estimated coastline of about 250 km, Vansjø is the largest lake in Østfold. With many creeks, islands and islets of all sizes, it’s a popular recreational area, ideal for swimming, kayaking, fishing, and walking.

Two of the largest islands on Vansjø, Dillingøya and Oksenøya, are linked by road to the shore, and are inhabited. A further two, Bliksøya and Langøya, also have road connection, although nobody lives there permanently, but there are several hytter (summer houses) on both.

Vestre Vansjø and Moskjæra have been nature reserves since 1992, and boast a rich bird life. Beavers too have been spotted in and around the lake. There are also 13 different fish species in Vansjø, including eel, bream, pike, perch and zander, making it a popular destination for anglers.

The name Vansjø is likely to come from ‘Varna sjor’, the old name of the district of Rygge. Contrary to popular belief, it has nothing to do with ‘vann’, the Norwegian word for ‘water’.

At its deepest point the lake is 41m deep, but the average is about 7m. It is used as a source of drinking water for the local area. Vansjø runs out into the Moss River (Mosselva), before reaching the Oslofjord just outside Moss.