Old Aker Church
Old Aker Church () is a medieval era church located in Oslo, Norway. An active parish, the church is the oldest existing building in Oslo. The church is surrounded by Old Aker Cemetery.
Calmeyer Street Mission House
The Calmeyer Street Mission House () was a building located at "Calmeyers gate" no. 1 in Oslo, Norway. The building served as a religious assembly house for Lutheran gatherings in the Oslo neighborhood around "Hausmanns gate" (Hausmann Street). 
Calmeyer Street Mission House was a Gothic Revival structure designed by the architect Henrik Nissen. Educator and businessman Otto Treider was largely responsible for the mission house being built in 1891. At the time, it contained Scandinavia's largest assembly hall, capable of accommodating over 5,000 people.