Suomenlinna Fortress (Swedish: Sveaborg – "Swedish Fortress") was founded in 1748 when Finland was part of the Swedish Kingdom. After its defeat in the Great Northern War, Sweden lost its eastern territories, and a powerful sea fortress was needed to protect Helsinki from the sea. The initiator and "father" of the fortress was Swedish Field Marshal Augustin Ehrensvärd, whose monument stands on the central square.
The construction was a grand project. Thousands of soldiers and convicts built a complex system of bastions, barracks, and arsenals directly on the bare rocky islands. The work lasted for several decades. By the end of the Swedish period, it was one of the most powerful sea fortresses in the world.
Major Historical Events
The Capture of the Fortress by Russia (1808): During the Russo-Swedish War (1808-1809), Sveaborg, considered impregnable, surrendered to Russian troops after a two-month siege. This predetermined the outcome of the war, and Finland became part of the Russian Empire as an autonomous Grand Duchy. The Russians significantly strengthened the fortress, building new forts and barracks.
The Crimean War (1855): An Anglo-French squadron bombarded the fortress, causing serious damage, but failed to capture it.
The Finnish Civil War (1918): After Finland gained independence, the fortress was used as a prisoner-of-war camp. It was then that it received its Finnish name Suomenlinna ("Finnish Fortress").
World War II: Anti-aircraft batteries were stationed here, protecting Helsinki from Soviet air raids.
Transfer to Civilian Authorities (1973): The military left the islands, and a new era began for Suomenlinna as a residential area, museum, and cultural center under civilian administration. In 1991, the fortress was included in the UNESCO World Heritage List as a unique monument of military architecture.
Territory and Layout of Suomenlinna Fortress
Suomenlinna is not a single building but an archipelago of 8 islands connected by bridges. Its layout is a classic example of a European bastion fortress.
• Central Part: The islands Susisaari and Iso Mustasaari form the historical core with the main fortifications, dry docks, square, and museums.
• The Dry Dock (Kustaanmiekka): One of the oldest structures, still in operation today. A grand engineering feat of its time.
• Line of Fortifications: Bastions, named after Swedish kings (e.g., the "Heron" bastion), form a continuous chain along the perimeter of the islands. The scenic Fortress Wall runs along the ramparts—an ideal route for a walk.
• Underground Casemates: A network of tunnels and rooms inside the fortress ramparts was used for storing ammunition and housing the garrison.
• Residential Quarters: Today, about 800 people live in the restored buildings, and there are cafes, artists` studios, and museums.
Brief List of Main Places to Visit:
Military Museum "Maneesi" (Sotamuseon Maneesi): Located in a former Russian artillery warehouse. The interactive exhibition is dedicated to Finland`s military history in the 20th century.
Suomenlinna Museum: The main historical museum of the fortress. It tells the 270-year history through artifacts, models, and archaeological finds. It`s best to start your tour here.
The Ehrensvärd Museum (Ehrensvärd-museo): Located in the founder`s mansion-palace. It preserves the atmosphere of the 18th century, with interiors in the Gustavian Rococo style, as well as Ehrensvärd`s personal belongings and paintings.
The King`s Gate (Kuninkaanportti): The symbol of Suomenlinna. Built in 1753-54 as the main entrance from the sea. It was here that the Swedish King Adolf Frederick stepped ashore to inspect the construction. A perfect photo spot.
Fortress Territory (Defensive Structures): The Dry Dock, bastions, fortress wall, and underground tunnels. Walking through them is the most exciting adventure, allowing you to appreciate the scale of the fortifications. Be sure to reach the farthest Kustaanmiekka Fort, which offers a panoramic view of the sea.
Visiting Tip: allocate a full day for Suomenlinna. Take the ferry from the Market Square (Hakaniemi). Wear comfortable shoes for walking on stones and grass. Pick up a map at the Visitor Centre by the main pier.
