Castillo de San Felipe was built in 1771 during the reign of Carlos III of Spain for the defense of the littoral. It was disarmed by the French army during the Spanish Independence War. Halfway into the 19th century it was occupied by the special forces in charge of the surveillance of the littoral. During the 20th century was abandoned and repaired between 1990-1991.
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.