Sitting on an island overlooking Lake Saimaa, Olvinlinna Castle is truly magnificent. Built to strategically protect the Savo Region, it became an important fortification against attacks from the Russians in the east. Every year since 1912, the castle holds its Annual Opera Festival, which attracts guests from around the world. The castle is open to the public daily and offers an impressive guided tour, which divulges all the secrets hiding within the castle walls.