Nanstein Castle was built around the year 1162 after Holy Roman Emperor Frederick I demanded its construction as additional defense for the Palatinate.
In 1504, German knight Franz von Sickingen, inherited part of the castle after his father's death in the War of the Bavarian Succession, finally acquiring the entire castle in 1518. He immediately began extensive refortification to make the castle suitable for firearms.
Nanstein is well known for an elaborate siege during the Knights' Revolt in 1523 which claimed the life of von Sickingen. The fall of Nanstein was a symbol for the decline of castles in the Palatinate.
In 1542, von Sickingen's sons recovered Nanstein as a fief and started reconstruction of the castle. Reinhard von Sickingen completed the reconstruction in 1595. In 1668, Elector Charles I Louis forced Lotharingian troops from the castle and razed the fortifications.
In the 19th century the first conservation work was done on Nanstein, and this has continued to the present day.
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.