Château de Saint-Félix-Lauragais was originally constructed in the 11th century. The first Synod of the Cathar church, known as the Council of Saint-Félix was held there in 1167. In the 14th century, the castle was transformed into a country house by a brother of Pope John XXII. The complex includes buildings from the 13th to the 18th centuries.
References: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.