Sværsvann is a lake in the southeast of

Oslo Oslo ( , , or ; sma, Oslove) is the capital and most populous city of Norway. It constitutes both a county and a municipality. The municipality of Oslo had a population of in 2022, while the city's greater urban area had a population of ...

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

. The lake drains off into the river

Hobølelva Hobølelva is a river rising in Sværsvann in Oslo, until joining Lake Vansjø in Østfold Østfold is a traditional region, a former county and a current electoral district in southeastern Norway. It borders Akershus and southwestern Swede ...

. The lake's surrounding areas are mostly residential. Sværsvann is a popular bathing place, and the name is believed to origin from "Sværd Vandet", which means "Sword Water", because a sword was once found at the bottom of the lake. The bottom water contains huge amount of salts, organic nutrition and hydrogen sulfid.

References

Lakes of Oslo {{oslo-geo-stub