Church of the Cross was a small medieval parish church for the northern part of the Old Town of Oslo. The ruin was rediscovered in 1922 and is now a part of the Ruin Park containing the ruins of the church and the greater St. Hallvard's Cathedral.
There is no definite information about when the church was built. The church is not mentioned in the sources of the fighting in Oslo in 1240 between King Haakon IV and Duke Skule, suggesting that it is possibly younger. In 1989 it was found a stick with runic inscriptions, dated to the first half of the 1200s. The name Church of the Cross occurs in this inscriptions, and it indicates that it may be older than 1240. When the church was built, it was located far north in the city, and an urban development north of the church came in the second half of the 1200s and the 1300s.
Church of the Cross had input from the west, from the cemetery, an entrance from the west and an entrance directly to the chancel from the south. The remains of the original altar foundation is visible. Around the church are the remains of the cemetery wall.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.