Top 10 Castles in Finland
Finland's castle tradition is a product of its geopolitical position as the eastern frontier of the Swedish realm from the 13th century. The castles built here were not primarily feudal residences but military and administrative instruments of Swedish expansion and frontier defence against the Novgorod Republic and later Russia. The result is a small number of major fortifications, several of which rank among the most significant medieval buildings in Scandinavia. Find them on the map.
1. Olavinlinna (St Olaf's Castle), Savonlinna
Olavinlinna, on a rocky island in the lake system near Savonlinna in eastern Finland, is the best-preserved medieval castle in Finland and one of the finest in northern Europe. Built from 1475 by Erik Axelsson Tott as a Swedish frontier fortress against Novgorod and Russia, its three surviving towers (originally five) and the connecting curtain wall stand to their full height in a lake setting of extraordinary beauty. The annual Savonlinna Opera Festival, held in the castle's inner courtyard each July, is one of the most famous opera festivals in the world.
2. Turku Castle, Turku
Turku Castle, at the mouth of the Aura river in Turku — Finland's medieval capital — is the oldest historical building in Finland. Construction began in 1280; the castle was expanded significantly in the 15th century and became the administrative headquarters of the Swedish realm's eastern province. John, Duke of Finland (later King John III of Sweden), made Turku Castle a Renaissance court in the 1560s, creating a brief cultural flowering that produced the castle's most significant decorative features. The castle houses the Historical Museum of Turku.
3. Häme Castle, Hämeenlinna
Häme Castle, on the shores of Lake Vanajavesi near Hämeenlinna in central Finland, is a large medieval fortress built by Sweden to control the inland trade routes of the Häme region. Construction began in the late 13th century; the current red brick castle dates substantially from the 14th-15th century. It served as an administrative and military centre, then as a prison from the 19th century. The castle now houses the Häme Castle Museum and is one of the best-preserved medieval fortifications in Finland.
4. Suomenlinna Sea Fortress, Helsinki
Suomenlinna — the Fortress of Finland — is an island fortress in Helsinki harbour built by Sweden from 1748 to defend against Russian expansion. The six-island complex, connected by bridges, was one of the largest fortification projects of 18th-century Europe. Russia captured it in 1808 after the Finnish War and used it as a naval base. It is now a UNESCO World Heritage Site (1991), a permanent community of approximately 850 residents, and the most visited tourist attraction in Finland after Helsinki itself.
5. Raseborg Castle, Snappertuna
Raseborg, above the Pojoviken bay in southwestern Finland near Snappertuna, is a ruined medieval castle built in the late 14th century by Swedish nobles on a rocky islet (now landlocked as the sea level has fallen). The castle was the administrative centre of the region; its ruins include towers, curtain walls, and the great hall. The annual Raseborg Medieval Market, held in the castle grounds each summer, is one of Finland's largest heritage events.
6. Kastelholm Castle, Aland Islands
Kastelholm, on the main island of the Aland archipelago, is the only medieval castle in the Aland Islands. Founded in the mid-14th century as a Swedish administrative centre, it was a centre of power in the Baltic for three centuries. It is associated with several notable Swedish royal prisoners; Eric XIV of Sweden was imprisoned here in 1571.
7. Kuusisto Bishop's Castle, Kaarina
Kuusisto, on an island in the Turku archipelago, was the residence of the Bishops of Turku from the late 13th century. The castle was deliberately destroyed in 1528 during the Reformation, when the Swedish Reformation programme required the demolition of Catholic ecclesiastical power centres. The ruins — substantial stone walls and a tower — survive on the island.
8. Korela Fortress, Priozersk
Korela Fortress, on an island in the Vuoksi river at what is now Priozersk in Russia (formerly Käkisalmi in Finland, controlled by Finland until 1941), was the principal Swedish-Finnish fortress on the Karelian Isthmus. Founded in the 13th century and contested between Sweden, Novgorod, and Russia through the medieval and early modern periods, it represents the eastern extreme of the Finnish castle tradition.
9. Viipuri Castle (Vyborg), Karelian Isthmus
Viipuri Castle (now Vyborg, in Russia) was founded in 1293 by Torkel Knutsson as the first Swedish castle in Karelia, establishing the frontier between Sweden-Finland and Novgorod. The castle's round tower, built in the 16th century, remains one of the best-preserved Swedish Renaissance military towers in existence. The castle is in Russian territory but represents the historical architecture of Finnish Karelia.
10. Crucifix Hill (Risti Kallio), Porvoo
The medieval fortress above Porvoo, Finland's second oldest city, is reduced to earthwork and stone remains; but Porvoo's role as the medieval fortified trading town and bishop's seat of eastern Finland makes it an important site in Finnish castle history even in the absence of standing structures.
Explore on the map
Finland's castle landscape — concentrated in the southwest and along the eastern frontier — is on the interactive map. Combining Olavinlinna, Turku, and Häme in a single itinerary gives a complete survey of the major surviving medieval fortifications.