Exmorra, Netherlands
13th century
Aldtsjerk, Netherlands
c. 1150
Dearsum, Netherlands
1200
Goutum, Netherlands
12th century
Hantumhuizen, Netherlands
c. 1200
Swichum, Netherlands
13th century
Augustinusga, Netherlands
15th century
Gytsjerk, Netherlands
12th century
Oentsjerk, Netherlands
c. 1230
Twijzel, Netherlands
1692
Easterlittens, Netherlands
12th century
Eastermar, Netherlands
13th century
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.