Sem Church was built in the 1100s as a parish church for the royal Sem Manor (Sem hovedgård). It has been restored and altered several times, 1690, 1770, 1924, 1955 and 1959. Near the church is a small burial chapel Det wedelske gravkapell for the noble family of Jarlsberg Manor. The pulpit dates from 1592 and altar from the 17th century.
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.