The origins of Randeck Castle are unknown, but in the tenth century Duke Arnulf may have built built the first medieval fortress on the hill in order to protect the land against the raids of the Hungarians.
Baron von Rotteneck is said to have built the castle in the 11th century. In the 13th century the Counts of Abensberg took possession of the castle. The owner Jack von Abensberg was known as robber baron and the city of Nuremberg waged war against him. In 1446 his castles were demolished and burnt down. Niclas, the last Count of Abensberg, was killed in 1485 in a feud with a neighbouring family.
The castle was attacked by Swedish army during the Thirty Years´ War. Both castle and convent were destroyed. In 1838 a large part of the castle just collapsed after heavy rainfalls.
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.