The Church of St. John was originally built on the site of the Headquarters of the Order of St. John around 1200.
In around 1400, the church was completely remodeled in the late gothic style, giving it its current appearance. The west choir loft was added between 1600 and 1628 and the upper floor was extended to form the town’s largest grain store. The Steinmeyer organ dates from 1885 and was restored in 2004.
Another interesting point is that the church underwent several confessional changes over the years. It became Protestant in 1553 as a result of Luther’s reforms. In the Thirty Years’ War the church provided a burial ground for Catholic officers. In 1803, as part of the secularization of Bavaria, it was transferred to the Catholic community as a pastoral center.
Bomarsund fortress and garrison was built in 1832-1854 by Russian Empire to defence Åland Islands against enemies. British and French fleet attacked against it during the Crimean War in 1854. After a week of fighting the British stormed the remaining fort. Anglo-French forces destroyed it totally after battle. In the Treaty of Paris 1856, the entire Åland Islands were demilitarized, which is a status that has been preserved until this day.
Nowadays there are some ruins left and fortress area is open for visitors.