The Northernmost Base of the Largest Fortress Chain in the Baltic Sea

At the beginning of the 20th century, Russia started to be worried about the territorial integrity of its capital Saint Petersburg. In order to control the security of the Gulf of Finland, the Russians constructed Peter the Great's sea fortress chain, which extended to the islands of Hiiumaa and Saaremaa, the Archipelago Sea and the northwest corner of the Åland Islands. Katanpää (constructed in 1915-1917) became the northernmost base of the largest fortress chain in the Baltic Sea. From there it was possible to control all three navigation routes running through the Archipelago Sea and prevent enemy access to the Turku Archipelago.

Granite cellar. Photo: Johanna Pakola

The Russians were not in control of Katanpää for very long and left the fortress in early 1918. The reds occupied the fortress for a couple of months during the Finnish Civil War. In 1925, Katanpää was turned into a guard post occupied by a few officers and conscripts. It is said that the 1920s were a peaceful time in the archipelago's fortresses. During World War II, Katanpää functioned as a checkpoint for the cargo ships heading to the Gulf of Bothnia. After the war, the Åland Islands were demilitarised and the other fortresses in the chain were abolished. Katanpää is the only fortress that remained in its original state as a monument to the fortress system's period of greatness. 

Beyond the Reach of Major Skirmishes and Active Use 

The remote location was one reason why Katanpää remained in its original state. Apart from minor skirmishes, Katanpää did not participate in war operations, nor was its building stock destroyed in the turmoil of war. And, due to the remote location, there have not been any modernisation pressures either. However, the original buildings have been renovated over the course of time. 

Island for Prisoners, Conscripts and Boaters

The Katanpää fortress has been visited more or less voluntarily over the years. At the beginning of the 19th century, the prisoners brought to the island from Amur and Manchuria by the Russians carefully laid two kilometres of cobblestone road on the island. In the 1930s, Finnish prisoners quarried paving stones and renovated the barrack buildings. The most unusual prisoner work was fishing, which produced fish for food and for sale.

The peacetime recruit training in the fortress began in 1953. The naval barracks were destroyed by a fire in May 1955, which crucially reduced the accommodation space and the training use. Katanpää was turned into a guard post in March 1955.

The coastal artillery extensively renovated the old buildings on Katanpää, and the island is now an open destination for all boaters. Visitors to Katanpää can admire nature and the small barracks area formed over the decades.