Komárno castle became the main supporting point of the defensive system constructed against the Turks, after they occupied Buda and Esztergom in the years 1541-1543. The fortress of Komárno is the one of the largest bastion fortifications in Central Europe. It was built in 1546-1557 to the grounds of the 13th century 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.