Senftenberg Castle was mentioned first time in 1197. In the 13th century it belonged to the Zebringer family and between the 14th and 15th centuries to the Wallseern family. The castle was destroyed during the rebellion in 1407-1409 and rebuilt later. It was a refuge place during the Siege of Vienna in the Ottoman Wars. The castle was finally destroyed by the Swedish troops in the Thirty Years' War in 1645. Today still impressive ruins with three gates and square keep exist.
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.