Old Aker Church
The church was built over the former site of the Akerberg mines ("Akersberg gruve"), an ancient silver mine which was in use since the early Viking era. The mines are mentioned in the 1170 "Historia Norvegiae". The existence of these former mines must have been the inspiration for a number of local stories about the church having hidden silver treasures and even dungeons with dragons.
Old Aker Cemetery () is the cemetery of Old Aker Church. Like the church, the cemetery dates back to the Middle Ages. The cemetery is located adjacent to the newer Cemetery of Our Saviour, which was established in 1808. Several notable people are interred in the cemetery.
Oslo Cathedral
Restoration was completed at the time of the city's 900 anniversary in 1950. The church was restored under the plans of architect Arnstein Arneberg. The neo-Gothic interior was removed and the original furnishings brought back. Arneberg also designed the chapel on the south side of the church. The church was closed in August 2006 for renovation and was opened in April 2010 in the presence of Harald V of Norway and the Norwegian royal family.The cathedral's first organ was built in 1711 by Carl Gustav Luckvitz, while the current main organ was built by Jan Ryde in 1997 for the 300-year anniversary. The two smaller organs in the cathedral were also built by Ryde og Berg Orgelbyggeri.In 1924 Oslo Cathedral received a donation of 24,000 NOK for a carillon in the belfry, but this was never implemented. In 2003 a second donation, by Ørnulf Myklestad, resulted in a 48-bell concert Carillon under the direction of carilloneur Vegar Sandholt. This carillon is inside the tower not the belfry, and the acoustical problems arising this location have been highlighted a 2005 masters thesis by Laura Rueslåtten.