Olavinlinna is built on an island in the Kyrönsalmi channel in Lake Saimaa. It has been the principal monument and symbol of the city of Savonlinna for 500 years.

1475 Sweden decides to begin construction of a castle at Kyrönsalmi on Lake Saimaa to end the border disputes in the region with Russia. Privy Counsellor Erik Axelsson Tott directs construction work at Olavinlinna, which is named after St. Olaf. First the small triangular main castle and three modern round towers designed to withstand the latest cannon are built: Church Tower, Bell Tower and St. Eric's Tower and the walls connecting them. Then the forecastle is built, in the courtyard of which the Savonlinna Opera Festival is held nowadays.

16th century Gustav Vasa decrees that Olavinlinna should be upgraded, the towers of the main castle are made higher and a large round cannon tower is built in the forecastle.

17th century Olavinlinna gains a fifth tower, Kijl Tower, and ancillary buildings are put up in the courtyard. Olavinlinna was principally a fortification and not for courtly life.

1714-1721 In the Great Northern War Olavinlinna is under Russian control. Under the Treaty of Nystad (Uusikaupunki) in...

1721 it is returned to Sweden.

1743 Under the Treaty of Åbo (Turku) south-east Finland including Savonlinna becomes part of Russia. Olavinlinna gains a ring of bastions and the cannon towers are increased in height.

1790s The castle becomes part of the defence front for St. Petersburg constructed under the command of General Alexander Suvorov.

1809 Olavinlinna loses its military significance. It is used for some years as a prison. Once vacated it falls into disrepair.

1870s Gradual restoration of Olavinlinna as a monument begins.

1912 The first Opera Festival is held at Olavinlinna on the initiative of the singer Aino Ackté.

1960s Large-scale restoration of Olavinlinna begins. The aim is to restore the castle as far as possible to its original appearance.

1967 The Opera Festival becomes an annual summer event. In 1974 the castle yard is covered over to protect it from rain.

1975 Restoration of Olavinlinna is completed for the castle's 500th anniversary. A swinging pontoon is built for the public, replacing the former ferry.

2000 The temporary rain cover and stage used for the summer festival are replaced.

Olavinlinna has been a tourist attraction and centre for cultural events for over 100 years. Apart from the annual Opera Festival, various events and private functions are held in the castle rooms and courtyards. Olavinlinna has two museums. Artefacts and other material from Olavinlinna are on show in the Castle Museum, whilst there are icons and ecclesiastical exhibits in the Orthodox Museum. The castle also has an ecumenical chapel, a summer café and a function room. There are guided tours all year round in several languages.

Olavinlinna and the surrounding area have been classified as a national landscape, and have been proposed as a Unesco World Heritage Site "Olavinlinna and the Saimaa Archipelago".