Alnsjøen (also called Alunsjøen) is a lake in

Lillomarka Lillomarka is an area located to the northeast of Oslo, Norway. It is a part of Oslomarka and serves as a popular recreational area. Lillomarka is bordered by Maridalen and Nordmarka in the west, Nittedal and Gjelleråsen in the east, the suburb ...

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 ...

, Norway. The lake is drained by the

Alna River The Alna River''Berlitz: Oslo Pocket Guide''. 2013. London: Berlitz. ( no, Alnaelva) is a river that runs through Oslo, Norway, from Alnsjøen to the Oslo Fjord at Bjørvika. It also drains Breisjøen, Steinbruvann, Tokerudbekken, and Øst ...

to the

Oslofjord The Oslofjord (, ; en, Oslo Fjord) is an inlet in the south-east of Norway, stretching from an imaginary line between the and lighthouses and down to in the south to Oslo in the north. It is part of the Skagerrak strait, connecting the Nor ...

. The surrounding area was utilized for

copper mining Copper extraction refers to the methods used to obtain copper from its ores. The conversion of copper consists of a series of physical and electrochemical processes. Methods have evolved and vary with country depending on the ore source, loca ...

during the 18th century. The lake functions as a minor

water reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

for the city of Oslo (the main water reservoir being the lake

Maridalsvannet Maridalsvannet ( en, Lake Maridal) is a lake in Maridalen, Oslo, Norway. It is the largest lake in the municipality of Oslo, and serves as the main drinking water supply for the city. The lake drains via the river Akerselva to the Oslofjord ...

). File:Alunsjøen 09-01-02.jpg, Alnsjøen in winter File:Alunsjødammen.jpg, The dam of Alnsjøen

References

Lakes of Oslo {{oslo-geo-stub