Næstved, Denmark
c. 1200
Rønne, Denmark
12th century
Ringkøbing, Denmark
15th century
Farum, Denmark
12th century
Nykøbing Falster, Denmark
1482
Allinge, Denmark
14th century
Nyborg, Denmark
1388-1428
Allinge, Denmark
12th century
Aakirkeby, Denmark
ca. 1165
Graested, Denmark
c. 1140
Skanderborg, Denmark
1060s
Praesto, Denmark
1225-1250
Vestervig, Denmark
1059
Nakskov, Denmark
13th century
Copenhagen, Denmark
1180s
Næstved, Denmark
1135
Bogense, Denmark
1406
Odense, Denmark
12th century
Hedensted, Denmark
c. 1150
Rømø, Denmark
c. 1200
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.