Krems castle history dates back to the 11th or 12th century. It was built by the Archbishop of Salzburg and mentioned first time in 1248. In the 16th century it was expanded and remodelled in Renaissance style. After 1730 the castle lost its position as administration residence and was left to decay. Today Krems ruins are well preserved. A small museum room opened in May 2015 exhibiting the history of castle.
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.