Zrin Castle was first mentioned in the 13th century as a fortress ruled by the Babonić clan. Between 1328 and 1347, it was possessed by the members of Iločki family. In 1347, King Louis I the Great bestowed the fortress to the noble Šubić family who then changed their family name after it, becoming the Zrinski. It remained in their possession until the Ottoman invasion and conquest of the region, which led to the fortress falling to them on 20 October 1577. It wasn't until 1718 that the castle was retaken from the Ottomans.
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.