Wikipedia
Alnsjøen
Alnsjøen (also called Alunsjøen) is a lake in Lillomarka in Oslo, Norway. The lake drains through the river Alnaelva to the Oslofjord. The surrounding area was utilized for copper mining during the 18th century. The lake is used as a water reservoir for the city of Oslo.
09-01-02.jpg|Alnsjøen in winter dam of Alnsjøen