Plavecký Castlee was built as a royal frontier castle between 1256 and 1273. Until the 16th century it was owned by Counts of Jur and Pezinok. In the second half of the 16th century the castle was rebuilt into a Renaissance style with the lower court. Gradually it was again fortified and maintained during the 17th century (new cannon towers were added then). In 1706 the castle was damaged the imperial army that conquered it from the rebels.
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.