Trelleborg is a collective name for six Viking Age circular forts, located in Denmark and the southern part of modern Sweden. Five of them have been dated to the reign of the Harold Bluetooth of Denmark (died 986). The city of Trelleborg has been named after one of these fortresses. Today Trelleborgen is part of a Viking Age fortress complex, which has been reconstructed. There is a Viking musem with souvenir shop, café and guided tours during the summer. Various events for both children and adults are also arranged during the summer to demonstrate how it must have been to live here in the Viking Age.
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.