Bomarsund
Updated:
Bomarsund[a] was built by the Russians in 1832 and destroyed twenty two years later in 1854 by a British/French fleet. It was at the end of the war, in the Treaty of Paris 1856, that the entire Åland Islands were demilitarized - a status that has been preserved since then.
Links
https://en.wikipedia.org/wiki/Bomarsund%2C_%C3%85land |