One of the largest sea fortresses in the world


Suomenlinna C 74, 00190 Helsinki, Finland

GPS: 60.145759195668, 24.983009977241

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Suomenlinna is an ancient maritime and military structure built off the coast of Helsinki, the capital of Finland. It means “fortress of Finland” in Finnish and is located on an archipelago of eight rocky islands. The fortress has been demilitarised since 1973 and is one of the most visited sites in the country.

The history of Suomenlinna began in 1748, when Finland was part of the Swedish Empire. As the Swedes wanted to protect themselves from a new Russian attack, they built a first defensive island base to protect the port of Helsinki. They named it Sveaborg (“Svea Fortress”) or Viapori in Finnish. The fortress enabled the small town of Helsinki to develop and grow rich through trade in the Baltic Sea. In 1808, the Russian Tsar Alexander I declared war on the Swedish King Gustav IV Adolf. Russian troops invaded Finland and seized the Fortress of Suomenlinna. Following the rapid surrender of Helsinki and Turku (the former regional capital of the Swedish Kingdom), the Treaty of Fredrikshamn was signed in 1809. This agreement obliged Sweden to cede the territory of Finland and the Åland Islands to Russia. The new capital of the Grand Duchy of Finland was transferred to Helsinki in 1812 by Emperor Alexander I. This Russian-Swedish war marked the beginning of Finland’s occupation for more than a hundred years until its independence in 1918, one year after the Russian revolution.

Under Russian administration, Suomenlinna entered a new era. Its perimeter was extended to other islands off Helsinki and military buildings were constructed to accommodate more soldiers. In 1855, the fortress was bombarded by a Franco-British fleet during the Crimean War. Heavily damaged, its fortifications were restored from the end of the 19th century. During the First World War, the site was used as a naval base to protect the city of Saint Petersburg, the former capital of Russia. After Finnish independence, Suomenlinna took on its present name and gradually turned to a residential, tourist and cultural function. The fortress was adorned with living quarters, museums, a school, a sauna, and an avant-garde prison. Known as the Gibraltar of the North, Suomenlinna is today inhabited by about 850 people and recognised by UNESCO as a unique example of military architecture. Its natural setting and rich history make it a popular picnic or strolling area for Finns due to its proximity to downtown Helsinki.

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  • The defensive walls, cannons, and former bunkers of the fortress
  • The network of underground tunnels and outer fortifications (six kilometres long)
  • The six museums on the island: the Suomenlinna Museum dedicated to the history of the site (open all year round), the Ehrensvärd Museum (named after the Swedish architect who built the fortress), the Vesikko submarine (a relic of the Second World War), the Military Museum’s Manege (on the Finnish army), the Suomenlinna Toy Museum (a collection of old objects) and the Customs Museum (history of smuggling in Finland)
  • The King’s Gate (Kuninkaanportti), the former main gate of the fortress
  • The walks, strolls and hikes around the ramparts and through the various islands of Suomenlinna
  • The view of Helsinki from the archipelago
  • Summer festivals and theatrical performances; gardens and picnic areas
  • The Helsinki International Artist Programme (HIAP), a residence and work space for an international community of artists
  • The old Helsinki market hall (Vanha Kauppahalli), where the oldest food market in the city is located (it is just a stone’s throw from Kauppatori market square)
  • The plans for the Fortress of Suomenlinna are inspired by the fortifications and bastioned constructions of Vauban (real name Sébastien Le Prestre). A former marshal of France under Louis XIV, this French engineer and architect was universally recognised as the specialist in fortifications, fortresses and defensive military works in Europe at the end of the 17th century.
  • Under the occupation of the Russians, who were predominantly Orthodox Christians, a church was built to satisfy their need for worship. Three years after Finnish independence in the 1920s, it was converted into an Evangelical Lutheran church. It is also used as a lighthouse to guide sea and air traffic.
  • The Suomenlinna Prison dates from 1971. It is a new type of prison, housing about 100 prisoners who are free to move around the archipelago as they wish, either to help with the physical maintenance of the island or to take the ferry to Helsinki to work outside or to visit their relatives. This Nordic model of an open prison structure aims to facilitate the reintegration process and reduce the risk of recidivism (the risk of recidivism is less than 20%, one of the lowest figures in the world). Prisoners, who must apply from a traditional prison to be accepted, are subject to community service and parole. Other similar penitentiary centres exist in the rest of Finland and allow this country to have one of the lowest incarceration rates in the world.
  • Beyond Suomenlinna’s best-known islands such as Korkeasaari (with a zoo) and Pihlajasaari (a group of islets with beaches), a total of 300 archipelagos are scattered around Helsinki.
  • The Finnish sauna is deeply rooted in the lifestyle, culture, and identity of the inhabitants. Its origins go back to the first peoples of Finland in the Bronze Age as an effective and vital means of combating the extreme cold in this northern country. The sauna has always been a sacred and mystical place with many functions: to give birth, to wash, to sweat, to provide the mortuary toilet, to heal, to wash clothes, to prepare food, to brew beer, to relax and to promote inner well-being (the heat releases endorphins in the body). It is also a great place for socialising without any professional distinction, as the participants dress in their simplest clothes. Collective saunas are generally set up in cities (buildings, companies, etc.), while many individual saunas in the form of wooden cabins (mökki) are located on the banks of a lake. Inside the hot room, the practice consists of regularly pouring water over hot stones to reach an ambient temperature of 70 to 110°C. It is customary to alternate sauna sessions with cold showers, rolling in the snow or swimming in the lake waters in all seasons (in winter, it is necessary to dig a hole in the ice). Finland has more than three million saunas for every five million inhabitants (equivalent to one sauna per household).
  • The Fortress of Suomenlinna is accessible by ferry from Helsinki. It takes about 20 minutes from the market square (Kauppatori) near the Presidential Palace. Depending on the season, the frequency and timetable of the ferries may change. In summer, the last ferry leaves Suomenlinna for Helsinki at 2 am.
  • The crossing is free for Helsinki Card holders. The ferry service is a part of the Finnish capital’s public transport system (some packages include access to the Finnish capital’s trams, buses, metro and suburban trains).
  • The fortress is easy to explore on foot. Start your itinerary at the Suomenlinna Visitor Centre to get a map of the complex.
  • Guided tours in several languages are given daily in June, July, and August (only on Saturdays and Sundays for the rest of the year).
  • When on site, bear in mind that many people live on the island all year round (be careful not to enter unauthorised areas). Some paths can be slippery in winter.
  • Most of the old tunnels are not lit, so it may be useful to have a torch.
  • Suomenlinna can be visited virtually in summer and winter through several 360° aerial views and immersions in its tunnels or historic buildings.

Where to eat

  • Café Vanille
    (on the Suomenlinna archipelago)
  • Soppakeittiö
    (soup bar)
  • Bastion Bistro
    (pleasant setting)

Where to go

  • Esplanadi
    (the heart of Helsinki)
  • Temppeliaukio Church
    (beautiful monolithic building)
  • Yrjönkatu Swimming Hall
    (sauna and public baths)

Where to stay

  • Hostel Suomenlinna
    (island hostel)
  • Innotelli Apartments
    (affordable flats)
  • Hotel Katajanokka
    (former prison)