A castrum is mentioned on the site of Château de Flamarens in 1289, and is believed to have been remodelled in the 14th century. Additional building work and alterations were made some time between 1469 and about 1475 by Jean de Cazanove for Jean de Grosolles. The northern part was built before 1536 by Georges Dauzières for Arnaud de Grossolles. Alterations were made to the windows and interior decoration in the 18th century. The castle was partially destroyed by fire in 1943.
The castle is privately owned.
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.