Step Into the Past: Exploring Finland’s Historic Castles

Among all castles in Finland, Turku Castle (Turun linna) is the heavyweight and one of the oldest surviving stone buildings in the country. Construction began around 1280, when the area formed the eastern part of the Swedish kingdom and needed a powerful fortress at the mouth of the Aura River to protect trade and authority. Over the centuries, this old castle grew from a compact keep into a sprawling complex serving as military stronghold, administrative center, and residence for high‑ranking nobles. Today Turku Castle is a fully functioning museum, with themed rooms that guide you from the Middle Ages through more recent times. Visitors can walk through vaulted halls, Renaissance apartments, gloomy prison cells, and narrow towers while reading signs that explain how the castle helped defend the region and organize daily life. Its mix of raw stone walls, restored interiors, and coastal city setting make Turku one of the most beautiful castles and an absolute must visit on any Finnish castle itinerary.

If Turku is the western anchor, Olavinlinna Castle is the eastern sentinel and one of the most photographed Finnish castles. Rising from a rocky island in Lake Saimaa at Savonlinna, Olavinlinna (St. Olaf’s Castle) was founded in 1475 by the noble Erik Axelsson Tott to secure the Savo region and defend Finland’s vulnerable frontier against eastern threats. Its compact plan, thick stone walls, and distinctive round corner tower show how late medieval castles adapted to the growing power of artillery. Inside, you navigate steep staircases, narrow passages, and inner courtyards that once echoed with cannon fire but now host guided tours, exhibitions, and seasonal events. In summer, Olavinlinna turns into an open‑air stage for the Savonlinna Opera Festival, transforming this former military fortress into one of Europe’s most beautiful castles to experience live music beside the water. For many visitors, combining a walk around the ramparts with an evening performance on Lake Saimaa is one of the best places to feel how culture and history blend in modern Finland.

Häme Castle (Hämeen linna) offers a different take on Finnish castles, rising in red brick above Lake Vanajavesi in Hämeenlinna. Probably begun in the late 13th or early 14th century, this compact fortress helped the Swedish Crown control the inland farming region between the south coast and central Finland. Its regular plan and thick bastions show a transition from irregular medieval keeps to more geometric designs that could better defend against gunpowder weapons.
Over time, Häme Castle served as noble residence, military fortress, and even a prison, before extensive restoration in the 20th century. Today the site combines a museum complex, exhibition spaces, and atmospheric courtyards where visitors can walk through rooms, climb towers, and look out over parkland and lake. Because of its central location, layered history, and distinctive red‑brick look, Häme is often recommended as one of the best castles in Finland for first‑time visitors.

Not every entry in a guide to castles in Finland stands on a hill; some stretch across the sea. Suomenlinna, spread over multiple islands off Helsinki, is a vast 18th‑century fortress and a designated UNESCO World Heritage Site. Built by Sweden as a maritime outpost to protect the capital and the Baltic approaches, it later became a Russian garrison and then part of independent Finland’s coastal defenses. Suomenlinna’s low stone walls, grassy bastions, and tunnels were designed to resist cannon fire and naval bombardment rather than classic medieval siege engines. Ferries run from the market square in central Helsinki, bringing visitors to a lived‑in neighborhood where they can walk along ramparts, visit small museums, and picnic in parks dotted with old guns and powder magazines. It may look more like a fortified archipelago than a traditional castle, but as a living sea fortress it easily ranks among the most beautiful castles‑and‑fortifications anywhere in the country.

Finland’s rail network makes castle‑hopping easy and comfortable, even on a short trip. Fast Intercity trains from Helsinki to Turku in about two hours, and from the station it’s a quick bus or taxi ride to Turku Castle on the Aura River. Trains to Hämeenlinna take roughly 1.5 hours, with Häme Castle located a pleasant walk or short local bus ride away along the lakeshore.

To visit Olavinlinna on Lake Saimaa, you can travel by train toward Savonlinna (often via a connection such as Parikkala), then walk from the station to the island‑based fortress. For UNESCO‑listed Suomenlinna, your rail journey ends at Helsinki Central: from there, walk or take a tram to the Market Square and board the frequent ferry to the sea fortress islands. Together, these straightforward routes let you link several Finnish castles into one scenic, rail‑based itinerary.

Farther north, the remains of Kajaani Castle and Oulu Castle tell quieter stories at the edge of the known world. Kajaani Castle was built in the early 17th century on a small island in the Kajaani River, meant as a compact fortress securing routes into the Kainuu region. After a dramatic siege it was blown up in the early 18th century, and today visitors find scattered ruins and foundations surrounded by water and forest. On the Gulf of Bothnia, Oulu Castle once helped guard trade and shipping lanes but was heavily damaged by explosions and fires. Only parts of the foundations remain, topped by a later pavilion, yet the site still draws people who want to trace the full chain of Finnish castles from coast to interior. These modest ruins remind you that fortifications once reached deep into a landscape still defined by lakes, forests, and long distances.

Viewed together, Finland’s castles form a timeline of shifting borders and competing empires. In the Middle Ages and early modern era, Turku, Häme, Olavinlinna, Raseborg, Kastelholm and their peers were tools of Swedish kingdom power, built to defend territory, collect taxes, and house officials across the eastern provinces. When Sweden lost ground to Russia in the 18th and early 19th centuries, several fortresses—especially Suomenlinna and newer coastal works—were pulled into a Russian system guarding the empire’s north‑western flank.
By the time of the world wars, traditional castles had lost their front‑line role, but Suomenlinna and coastal defenses still mattered during World War II and the Second World War period, as Finland fought to defend Finland from invasion. Museum displays in major Finnish castles often connect medieval conflicts with more recent fighting, showing how the same landscape saw arrows, cannons, and aircraft within a few hundred years. That long arc of conflict and adaptation gives these fortress sites a fascinating history that goes far beyond romantic images.