Hammeren Hydroelectric Power Station

St. Margaret's Church (Norwegian: Margaretakirken) was a medieval stone church located on the outskirts of Oslo, Norway.The church was built in the 13th century, and is now a ruin. The church is named after Margaret of Antioch. It was located in Maridalen, close to the northern end of lake Maridalsvannet. Architect and archaeologist Gerhard Fischer led the restoration in 1934. Today it is the best preserved medieval building in Oslo next to the Old Aker Church.

Maridalen Church is a wooden church in Maridalen at the northern outskirts of Oslo, Norway, next to Nordmarka. The church was originally built as a mission house (Bedehus) in at the northern shore of the lake Maridalsvannet in 1887. It was taken over by the Church of Norway and consecrated first as a chapel in the year 1900, later renamed a church.Maridalen Church is located not far from the ancient church ruins of the medieval church St Margaret's Church.Maridalen Church has about 140 seats. The altarpiece is depicting Jesus in Gethsemane. The small bell tower has one church bell from 1898.Maridalen Church is listed by the Norwegian Directorate for Cultural Heritage.

Maridalen is a valley situated just north of Oslo, Norway, just above the suburb of Kjelsås. Considering that Maridalen is within the Oslo city limits, Maridalen has a very low population density. The valley consists of forests, lakes and agricultural land. Most of the valley is made up of the lake Maridalsvannet, which serves as the primary source of drinking water for 90% of Oslo's population. The only hydroelectric powerplant within the City of Oslo, Hammeren Hydroelectric Power Station is located at Brekke in Maridalen. The valley is a popular recreational area with many hiking trails and cycling tracks for summer usage, and groomed cross-country trails in winter. Both the lake and valley are protected. Maridalen Church and the church ruins of the ancient St. Margaret's Church are located north of Maridalsvannet. A bus route runs along Maridalen, starting at Nydalen Subway Station.

Sognsvann (or Sognsvannet) is a 3.3 km circumference lake just north of Oslo, Norway. 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 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. 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.

The National Archives of Norway in Oslo (Norwegian: Nasjonalarkivet i Oslo), before January 1 2026 the National Archives of Norway and the Regional State Archives in Oslo, is a state archive situated at Sognsvann in Oslo, Norway. Part of the National Archives of Norway, it is responsible for archiving documents from state institutions in the counties of Akershus, Oslo and Østfold. The collection includes 19.2 shelf-kilometers of material. The National Archives of Norway in Oslo is the institution responsible for preserving archive material from Norwegian state institutions, as well as contributing to the preservation of private archives. The National Archives (Norwegian: Riksarkivet) was founded in 1817. Henrik Wergeland was appointed as the first national archivist in 1841. The Regional State Archives in Kristiania was created in 1914, and initially covered all of Eastern Norway and Agder. From 13 July 1917 the newly created Regional State Archives in Hamar took over documents from Oppland and Hedmark. The name the Regional State Archives in Oslo was adopted in 1924. With the opening of the Regional State Archives in Kristiansand in 1934, documents from Agder was moved there. The final demerger took place in 1994, when the Regional State Archives in Kongsberg took over documents from Buskerud, Telemark and Vestfold. On January 1 2026, the National Archives of Norway and the Regional State Archives were merged and named the National Archives of Norway in Oslo.

The National Archives of Norway (Riksarkivet) is the institution responsible for preserving archive material from Norwegian state institutions, as well as contributing to the preservation of private archives. It does this work in cooperation with the regional state archives, together with which it forms the National Archival Services of Norway (Arkivverket).The National Archives was founded in 1817. Henrik Wergeland was appointed as the first national archivist in 1841.

The National Archival Services of Norway (Norwegian: Arkivverket) is a Norwegian government agency that is responsible for keeping state archives, conducts control of public archiving and works to preserve private archives. It is subordinate to the Ministry of Culture and Church Affairs and consists of the National Archive (Riksarkivet), eight regional state archives (statsarkiv) and The Sámi Archives (Samisk arkiv). The organization has 190 employees and about 120 kilometers (75 mi) of materials. The oldest complete document is from 1189. It is a letter (a so-called diploma) issued on 28 January 1189 by Pope Clement III (1187-1191) to all clergymen in Norway.The National Archive is located at Sognsvann in Oslo and preserves all central government papers from when they become 25 years old, as well as some archives from private individuals, companies and organizations. The National Archive is also responsible for control. The state archives are responsible for local and regional government and state agencies, as well as archives from private people, companies, institutions and organizations. The local archives are located in Bergen, Hamar, Kongsberg, Kristiansand, Oslo, Stavanger, Tromsø and Trondheim.The Digital Archive is a web site that publishes selected works. This includes census data from 1801, 1865, 1875, 1900 and 1910, a database of emigrants and scanned church, probate and court records. The agency publishes three magazines: Arkivmagasinet, Nytt fra Statsarkivet i Oslo and Bergensposten. The agency is regulated by the Archive Act of 1992. The archives are open to anyone, but there are restrictions on certain types of documents that may contain sensitive or personal information, or could pose a threat to national security. These documents are released to the public between 60 and 100 years after the date of publishing.

Toppidrettssenteret (English: The Elite Sports Centre) is the training center of the Olympiatoppen, the elite branch of the Norwegian Olympic and Paralympic Committee and Confederation of Sports. It is located between the Norwegian School of Sport Sciences and the recreational area Sognsvann. The main building consists mainly of training rooms. Outside there are an association football pitch with artificial turf, an all-weather running track, an athletics throwing field, a bandy field, a basketball court, and facilities for skating and lugeing. There is also a medical facility as well as a hotel.

Sognsvann is a rapid transit station of the Oslo Metro's Sognsvann Line. It is situated Kringsjå neighborhood of the Oslo, Norway, borough of Nordre Aker. Located 8.7 kilometers (5.4 mi) from Stortinget, the station is served by Line 5 of the metro every fifteen minutes. Travel time to Stortinget is sixteen minutes. The station opened on 10 October 1934 at the same times as the rest of the Sognsvann Line. The station received a major upgrade in 1993, in which it received longer platforms. The new station was designed by Arne Henriksen. The station is located next to and serves the Norwegian School of Sport Sciences and the National Archives of Norway, as well as the recreational area around the lake of Sognsvann.

Korsvoll is an area in the borough Nordre Aker in Oslo, Norway. The area is located between the areas Brekke and Nordberg, northwest of the old industrial area Nydalen. The area borders on the forest area Nordmarka, and is a popular residential area for families. The local sports club is Korsvoll IL. The local school is Korsvoll primary school, placed close to the forest area.

The Norwegian School of Sport Sciences (Norwegian: Norges idrettshøgskole, NIH) is a public university located at Sognsvann in Oslo, Norway. It has the national responsibility for education and research related within sport sciences. It provides education at the Bachelor, Master and Doctorate levels.

Nordberg Church is a hexagonal church, located in the neighbourhood of Nordberg in Oslo, Norway.The church was completed in 1962 and was restored and expanded with a church parlor in 1982. The facade is in white bricks and has a characteristic church tower which can be seen from large parts of the city of Oslo. It is one of the largest churches in the city.The altar tapestry, The Resurrection is made by Kari-Bjørg Ile. It came into place in 1992. The pulpit and the baptismal font are made according to the architects' drawings. The current church organ from 2015 is a digital organ of the type Johannus Monarke Präludium.There are two church bells from Olsen Nauen Bell Foundry in the church tower.Outside the church is a log house, a former chapel used for the church's nursery.The church is listed by the Norwegian Directorate for Cultural Heritage and protected by Norwegian law.