Laubenbergerstein is a hilltop castle, likely established in the 12th century by the Bishops of Augsburg, aimed to safeguard the crucial Iller River crossing and associated customs station. Initially occupied by the Laubenberg family, the castle experienced conflicts, including attacks in 1449 by Graf Hugo XIII. von Montfort. Kaspar von Laubenberg initiated substantial expansions after 1450, resulting in the dominant artillery keep. During the German Peasants' War in 1525, the castle was seized and weapons were stolen.
In 1559, the Laubenberg family left the castle for a newly built residence in Rauhenzell. By 1629, the castle was already considered a partial ruin. Margaretha von Laubenberg accelerated its decay in 1641, selling roofing tiles. In 1647, the fief was revoked, and by 1806, the castle came under Bavarian rule. In 1977, the Immenstadt Heritage Association acquired the ruins and began restoration efforts. The castle, made of local materials, is now accessible to visitors. The imposing artillery tower, constructed after 1450, dominates the castle's appearance and can be climbed on special occasions.
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.