The Fort Bokar, often called Zvjezdan, is considered to be amongst the most beautiful instances of harmonious and functional fortification architecture. Built as a two-story casemate fortress by Michelozzo from 1461 to 1463, while the city walls were being reconstructed, it stands in front of the medieval wall face protruding into space almost with its whole cylindrical volume. It was conceived as the key point in the defense of the Pila Gate, the western fortified entrance of the city; and after the Minčeta Tower, it is the second key point in the defense of the western land approach to the city.
Bokar is said to be the oldest casemented fortress in Europe, which contains a small lapidary collection and numerous cannons.
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.