Haslum church was built in c. 1190 in Romanesque style. It is possible that it was built by Cistercian monks who also built Halvard Cathedral in Oslo. The original long nave was altered to cross shape in the 1200s. In 1300 there were 12 altars in the church. Haslum church was reconstructed in 1853 and restored to the medieval appearance in 1924.
The wooden statues of the Virgin Mary and the Bishop are copies of medieval originals that have been moved to the Antiquities Collection at the University of Oslo. The Renaissance altarpiece (1631) and pulpit (1590-1642), as well as the baroque baptismal font (1736) are worth of seeing. The paintings on the ceiling were executed by Axel Revold in 1920.
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.