Thierstein Castle was built in the early 14th century by Albrecht VI of Wildstein. Later it was moved to the hands of Nuremberg burgraves and the house of Hohenzollern. In 1553, during the Second Margrave War, Thierstein was occupied by Bohemian troops. In 1603 Margrave Georg Friedrich of Brandenburg ordered to abandon the castle and the construction of a new office building outside the village of Thierstein. Nevertheless, the most necessary repairs were still carried out at the Thierstein castle during the Thirty Years' War. The end of the Thierstein castle came in 1725, when it was destroyed by fire.
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.