Kyminlinna Fortress

Sutelantie, Kotka
  • Kyminlinna Kotka
  • Kyminlinna ilmakuva

The Kyminlinna Fortress was planned by the Russians in the 1790s as part of a system of defences for St. Petersburg. The original fortress was torn down later and replaced with a more up-to-date fortress. It is Finland’s only caponier fortress that has survived intact. Kyminlinna is five kilometres northwest of the centre of the city of Kotka at the confluence of the eastern (Huumanhaara) and western (Langinkoskenhaara) branches of the River Kymijoki. The site can be freely visited on the outside, but entrance into the actual fortress requires the presence of a guide.


  • 15th c. A manor and chapel are founded in the present area of Kyminlinna.    
  • 1556 King Gustavus Vasa of Sweden visits the manor and converts it a so-called royal manor owned by the crown. Defensive works are constructed in the area
  • 1743 As a result of the Swedish-Russian War 1741–1743, Sweden loses more territories to Russia, including the area of Kyminlinna.
  • 1791–1792 A fortress designed by General Aleksandr Suvorov is built in the area.
  • 1803 The new fortress of Kyminlinna comes under construction and Suvorov’s fortress is torn down. Kyminlinna was a modern fortress for its period.
  • 1809 The eastern parts of Sweden are ceded to Russia as the result of the war of 1808 –1809. The unfinished fortress of Kyminlinna loses its importance as a border stronghold.
  • 1819 The Kyminlinna Fortress is converted into a military depot.
  • 1855 A new period of construction begins at Kyminlinna. Military encampments are held there in the summer months.
  • 1918 The only battle in the history of the fortress is fought on the 9th of April between the Finnish Red Guard and German troops. After the Finnish civil war of 1918, the Kyminlinna Fortress area served as a temporary camp for imprisoned members of the Red Guard.
  • 1922‒1939 A centre for Karelian and Ingrian refugees operates at the Kyminlinna Fortress.
  • 1939 Kyminlinna is taken into use by the Finnish Defence Forces.
  • 1982 Restoration of the Kyminlinna Fortress begins.
  • Early 2000s Research, repairs and landscaping carried out in the area. The military garrison moves out in 2005.


The Kyminlinna Fortress is on Hovinsaari Island at the confluence of the branches of the River Kymijoki. During the Middle Ages, the coastal highway between the castles of Turku in the west and Viipuri in the east passed through the island. There were properties owned the by the king in the present-day Kyminlinna area already in the 14th century. The importance of the location is indicated by the fact that the original manor there was converted into a so-called royal or king’s manor in the 16th century. The manor included a chapel. At present the manor is on the river bank north of the fortress.
Royal manors usually included defensive fortifications. There is definite information on fortifications in the area from the 17th century, when there was a small fort of earthworks at the site. The Kyminlinna area was passed to Russia in the Swedish-Russian War of 1741 –1743.
The Russians began to improve the defences of their western border and a guard-post fort designed by General Aleksandr Suvorov was built on Hovinsaari Island in 1791. Kyminlinna was part of the zone established by the Russians for the defence of St. Petersburg. The fort was over 200 metres in diameter. Kyminlinna and the subsequently demolished naval fortress of Ruotsinsalmi (Svensksund) formed a double fortress.

The fortress consisted of the main fort, adjacent defensive works and outworks. The main fort consisted of two bastions and two smaller fortifications each containing a demi-bastion. The main fort was surrounded by a moat and a wall of natural stone. Small trap pits were arranged as the outermost features.
The layout of Kyminlinna began to be criticized immediately after General Suvorov left Southeast Finland. The fortress was regarded as small and outmoded. The new fortress of Kyminlinna designed by the fortifications engineer Jaan Peter von Suchtelen came under construction in 1803. Suvorov’s fortress was torn down and its material was reused in the new fortress, which was six times larger than the old one.

Almost 500 metres in diameter, the new Kyminlinna Fortress consisted of five bastions with angled walls running between them. The defensive works built on Hovinsaari Island formed an efficient and up-to-date caponier fortress, i.e. specialized in close-range and flanking defence. Close-range defence was improved by constructing separate fortifications known as caponiers in connection with the moats.

In 1809, Finland became an autonomous Grand Duchy of the Russian Empire. The border between Sweden and Russia moved and the Kyminlinna Fortress turned into a remote outpost. Its construction was halted since it lost its role as a border fortress. By that time, auxiliary buildings, gateway guard posts, a main guard building, barracks and a kitchen building had been constructed at the fort. Kyminlinna became a military depot and its defensive structures and buildings began to fall into disrepair.

A new period of construction began in the 1850s at the Kyminlinna Fortress. Wooden buildings were erected and encampments were held in the summer months. Kyminlinna operated as a Russian garrison until Finnish independence in 1917.
In 1918, the only battle ever fought at Kyminlinna took place between the Finnish Red Guard and German troops. The fortress served as a temporary camp for imprisoned Red troops after the Finnish civil war of 1918. In the inter-war years it was a centre for Karelian and Ingrian refugees. There was also a hospital for contagious diseases at the fortress. After the Second World War, Kyminlinna was a military deport and for over 50 years a garrison of the Finnish Defence Forces. The garrison was moved to Hamina in 2005.

The Kyminlinna Fortress had fallen into disrepair by the 1980s. During the course of the decade, the main wall, outer defences and earthworks were repaired. In the 21st century refurbishment has continued and archaeological fieldwork has been carried out. The area has revealed graves from the 15th –18th centuries and objects from the 19th and 20th centuries.



Kyminlinna is Finland only caponier fortress surviving intact, i.e. originally specialized in flanking and close-range defence. It is therefore a valuable monument of military history. The main walls and the interior parts of the fortress have survived well, but roads and a railway now pass through the outer defensive works. Two of the caponiers for close-range defence have been renovated. One of them now serves the Kyminlinna summer theatre.

Remains of the Suvorov fortress can be seen inside the main walls and there are some 20 trap pits measuring 1-2 metres in diameter in the terrain. The stone foundations of the main gate and an angled curtain wall also survive.

Inside the fortress are early 19th-century guard post buildings, two barracks buildings and a kitchen building. The northeast gate has been restored to its appearance in the 1930s and the southwest gate to its original appearance.
The fortress area is currently vacated and new uses for it are being studied. There is free access to the outdoor areas of the fortress throughout the year, but entrance within the gates is permitted only in the company of a guide.

National Board of Antiquities, Satu Juopperi
From Castle to Castle -network's guide book

Suomalaiset linnoitukset 1720-luvulta 1850-luvulle (Ed. V.-P. Suhonen). Suomalaisen kirjallisuuden seura. Helsinki 2011.
Kauranen, Veli: Suomen vanhat linnat, kartanolinnat, linnoitukset ja skanssit. Hämeenlinna: Karisto oy:n kirjapaino, 2005.
Restoration webpages of the National Board of Antiquities,
Valtakunnallisesti merkittävät rakennetut kulttuuriympäristöt, Museovirasto,