Solidor Tower (tour Solidor) is a strengthened keep with three linked towers, located in the estuary of the river Rance. It was built between 1369 and 1382 by John V, Duke of Brittany (i.e. Jean IV in French) to control access to the Rance at a time when the city of Saint-Malo did not recognize his authority. Over the centuries the tower lost its military interest and became a jail. It is now a museum celebrating Breton sailors exploring Cape Horn.
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.