Réserve naturelle d'Østensjøvannet

Østensjøvannet (pronunciation ) is a lake located in the Østensjø borough in Oslo, Norway. It is well known for the wide variety of birds and other wildlife that can be found there. It is currently a wildlife preserve, though urban development posed a serious threat to the lake and its environs during the 1980s and early 1990s.

Østensjø ([ˈœ̂sːtn̩ʂøː] (listen)) is a district of the city of Oslo, Norway.The district is in the southeastern part of Oslo. It is well known for its proximity to the forested area of Østmarka, a popular resort and hiking area for the citizens of Oslo and Lørenskog. Østensjø consists of the suburbs of Bøler, Oppsal and Manglerud, all located around Lake Østensjøvannet.

Manglerudhallen is the name of two arenas, an indoor ice hockey arena and a multi-purpose indoor arena, located in Manglerud, Oslo, Norway. The capacity of the ice hockey arena is 2,000 and it was opened in 1979. It is the home arena of the Manglerud Star ice hockey team.

Oppsal is a station on Østensjø Line (line 3) on the Oslo Metro, located in the suburb Oppsal between the stations of Skøyenåsen and Ulsrud, 7.8 kilometers (4.8 mi) from Stortinget. The station was opened as a subway station 29 October 1967. P.A.M. Mellbye was the station's architect. Rail service through Oppsal is older, having opened as a tram line already in 1926.