Dalarö fortress was built by Charles X Gustav of Sweden in 1656. It replaced an old structure from 1623. In 1683 the fortress was renovated by Erik Dahlbergh and the renovations were completed in 1698. The fortress has never been under siege and therefore well-preserved. It was decommissioned by the military in 1854. Today the building is a museum and it contains a restaurant.
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.