The Tour des Archives is the keep of a former castle. Its origin goes back to 1123, built by King Henry I of England, the son of William the Conqueror. It is 22m high and is a rare existing example of a round tower in Normandy, like the so-called tour Jeanne d'Arc (Joan of Arc Tower) of the former Rouen Castle. The Tour des Archives has been classified since 1840 as a monument historique by the French Ministry of Culture.
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.