Enlarge Reduce


Situated on a group of islands off Helsinki, Suomenlinna was built during the Swedish era as a maritime fortress and a base for the Archipelago Fleet. Work on the fortress was begun in the mid-18th century. Today, it is a UNESCO World Heritage Site and one of Finland’s most popular tourist attractions. Suomenlinna is also a district of the city of Helsinki, with a permanent population of more than 800.

Suomenlinna in winter, Suomen Ilmakuva Oy
Built on a cluster of rocky skerries, the fortress consists of an irregular network of bastions. During the Russian era, the fortress was extended both towards the sea and on the mainland.

Suomenlinna has played a key role in many turning points in Finland’s history. It has been the property of three sovereign states. The majority of its buildings date from the late 18th century, the end of the Swedish era. From the early 19th century to the early 20th century, Suomenlinna – then known as Viapori – was part of Russia along with the rest of Finland. Russian-era Viapori was a lively garrison town. After Finland gained her independence, Suomenlinna became home to a coastal artillery regiment, a submarine base and the Valmet shipyard, where ships were built after the Second World War for Finland’s war reparations.

Suomenlinna today

Suomenlinna is the property of the Finnish government and is managed by the Governing Body of Suomenlinna, an agency subordinate to the Ministry of Education and Culture. The fortress was handed over to civilian administration by the military in 1973 with the exception of Pikku Mustasaari island, where the Naval Academy is still located. The Finnish customs authorities have an office on the islands, and Suomenlinna also houses the Suomenlinna prison. A substantial part of the repairs to the walls, ramparts and buildings are carried out by convicts.

The old buildings are still in everyday use as housing, working space, maintenance facilities and visitor service facilities. There is a continuous building repair programme going on. The restoration of fortifications and old buildings requires considerable expertise. The 18th-century dry dock on Susisaari island is still used as a winter storage and repair facility for old wooden sailboats. There are dozens of historical underwater sites around the fortress.

The natural environment on Suomenlinna is a mixture of indigenous Finnish archipelago ecosystems and centuries of horticulture. Many migratory birds stop on Suomenlinna, and several species of birds such as barnacle geese and swans nest on the islands.


Fortification wall
  • 8 islands: Kustaanmiekka, Susisaari, Iso Mustasaari, Pikku Mustasaari, Länsi-Mustasaari, Särkkä, Pormestarinluoto and Lonna.
  • Area: land 80 hectares, surrounding sea 80 hectares.
  • Length of walls: about 6 km
  • Artillery: 105 cannon.
  • Buildings: 200 (160,000 square metres).
  • Inhabitants: about 850
  • Jobs: 400 around the year, 500 in the summer.