Founded by Franciscans in 1233, St Karins Kyrka is one of the most stunning of Visby’s medieval churches, with a beautiful Gothic interior. Other ruins include the magnificant St Nicolai Kyrka , built in 1230 by Dominican monks. The Helge And Kyrka ruin is the only stone-built octagonal church in Sweden. It was built in 1200, possibly by the Bishop of Riga; the roof collapsed after a fire in 1611.