The St. John's Church in the Hamina city centre was built in 1841-1843. It was designed by famous architect Carl Ludvig Engel and represents the Neoclassicism style with strong influence of Greece temples.
Before the present church there was a church of Ulrika Eleanora (built in 1732, destroyed by fire in 1742) and the commandant’s house. The residence of the fortress commander was the place where the Russian negotiators lived and signed the Treaty of Hamina (after the Finnish War in 1809).
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.