Sognsvann (or ''Sognsvannet'') is a 3.3 km circumference
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much lar ...
just north 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 ...
.
Lying just within the greenbelt around Oslo, the lake is a popular recreational area, used as a camping, picnicking and bathing destination for the residents of Oslo during the summer, as well as a cross-country skiing, skating and
ice fishing
Ice fishing is the practice of catching fish with lines and fish hooks or spears through an opening in the ice on a frozen body of water. Ice fishers may fish in the open or in heated enclosures, some with bunks and amenities.
Shelters
Lo ...
destination in the winter. The trail around it is used for walking or jogging all year. Every year in August, swimming and running take part in Sognsvann as part of the Oslo Triathlon.

Cycling on the footpath around the lake is prohibited; however there is a dedicated cycling trail. Disabled access is good to and around the lake.
Part of the lake's popularity stems from its easy access from Oslo;
Sognsvann station, located on the south end of the lake, is the final stop on line 5 on the
Oslo Metro
The Oslo Metro ( no, Oslo T-bane or or simply ) is the rapid transit system of Oslo, Norway, operated by Sporveien T-banen on contract from the transit authority Ruter. The network consists of five lines that all run through the city centre, w ...
.
Svartkulp ("The black pool"), a small forest lake which is one of three
nudist beaches in Oslo, lies a few hundred meters to the east of Sognsvann.
Nedre Blanksjø ("The lower shining lake") is an even smaller lake a few hundred meters to the north of Svartkulp. A pyramid marking the
geographical center of Oslo municipality and county is installed on the east side of it, alongside
Ankerveien.
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 ...