Finland's independence was defended on the fortress island of Ulko-Tammio

Located in the eastern part of the Gulf of Finland, about 30 kilometres from the city of Hamina, the island of Ulko-Tammio is less than 10 kilometres from the Russian border. The island was uninhabited for a long time and only used as pasture for the nearby village on Tammio Island. Originally, Ulko-Tammio Island consisted of two smaller islands. Between these islands, the approximately ten metre wide neck of land was filled in from 1939 to 1944, during the Winter- and Continuation Wars.

The fort was built to protect the eastern border

The island of Ulko-Tammio played an important role when it was taken over by the Finnish Armed Forces as an observation post during the Winter War. The island was prominently located near Soviet-occupied areas, such as the islands of Gogland (Fin. Suursaari), Sommer (Fin. Someri), and Nerva (Fin. Narvi).

A close-up of the parish map from 1847.

Actual fortifications were built during the ceasefire between the Winter and Continuation Wars, and the island became a guard post on the eastern border of Finland. A coastal artillery fort operated on the island and anti-aircraft stations, searchlights, and watch towers were also built. Additional cannons and other ammunition were brought to the island, which also had a landing site for submarines, as well as a naval support base.

No actual military action ever occurred on the island, even though there was actual conflict in the surrounding areas. However, some soldiers were wounded when Russian aircraft bombed the island several times in 1943 and 1944.

During the Continuation War, the Ulko-Tammio Fort took part in the battle for control of the coastal fortress on Sommer Island. This island was bombarded from Ulko-Tammio using heavy cannon, which had a range of 19 kilometres. Although Sommer Island was defended by just under a hundred men, they were still able to fend off an overwhelming enemy. Today, there is a war memorial to the Battle of Someri on the island Ulko-Tammio.

Although the fort’s tactical complement of men and the amount of weaponry varied at different stages of the war, the Finnish defence was always in a state of readiness. The fort was at its strongest in September 1944, when its total strength was 370 men.

The war ended in September 1944 and the fortress had to be disarmed under the ceasefire agreement. The heavy cannon was removed from the island and the fortress buildings were sold to civilians.

Visitors can experience the island's military history and the isolation of the high seas

Ulko-Tammio Island is currently uninhabited. The secluded island hides many wartime remains, including two museum cannons, cannon stands, trenches, ammunition stores, as well as an approximately 70-metre long cave designed to protect personnel. The cave can be explored, but you should take a flashlight with you. Memorial plaques and soldiers' graves tell of the wartime ordeals.

The nature of this secluded island is diverse and impressive with its rugged cliffs and groves of broad-leaved trees. Here you can experience the power of the high seas, while enjoying the physical distance from everything else. Rare birds and plants are protected by the island’s isolation. 

At the highest point of the island is a bird observation tower with a magnificent view of the National Park. In good weather, you can also see Bolshoi Tyuters- (Fin. Tytärsaari), Gogland- and Sommer Islands, which lie in Russian territory. The Finnish Coast Guard has an unmanned radar station and a cabin on the island of Ulko-Tammio.

The island of Ulko-Tammio is a popular tourist destination during the summer. Visitors can stay in a wilderness cabin, which was adapted from a wartime barracks built in 1939. Dozens of rock drawings dating back to the 19th century can be admired at the nearby tiny islet of Ulko-Tammio, which is located east of the main island.

Read more:

The Ulko-Tammio webpage of the

The website of the Kotka-Hamina Municipality

Rockcarvings in Ulko-Tammio cliffs.

Why and how is this location protected?

Its remote location has played an important role in defending Finland's independence. Metsähallitus manages and maintains the site. The island is also part of the Eastern Gulf of Finland National Park.


Ulko-Tammio Island is accessible from Hamina by ferry during the weekends of June and July, when the Metsähallitus guide is also on site. The island can be explored independently throughout the year, weather permitting. The island has a nature trail and free accommodation.

Finnish Heritage Agency's mapservice

N: 6690203, E: 525237 (ETRS-TM35FIN)