The main building of 's Herenelderen has been rebuilt in different periods. The oldest late Gothic style part is in the northwest corner and dates from the 16th century. The castle consists of three floors. The two brick building parts are built in Baroque style and date from the end of the 17th century. At the end of the 18th century, the courtyard was altered in the Louis XVI style.
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.