Herrstein Castle, on the north side of the town settlement, was built in the latter half of the 13th century by the Counts of Sponheim. The upper castle had originally four towers at the ringwall’s corners, three of which are preserved. The former castle chapel has been since the 15th century a parish church. On the site of the bailey so-called Schloss (palatial castle) built in 1742.
Evangelical parish church Schlosskirche is a single-naved building, partly Gothic, partly Baroque. A quire arch and east part of the south wall date possibly from the late 13th 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.