Olavinlinna

The northernmost medieval stone fortress still standing, and the best preserved of any castle in the old Swedish realm, a three-tower keep on an island in the Kyrönsalmi strait between two lakes. Erik Axelsson Tott founded it in 1475 to exploit the turmoil after Ivan III took Novgorod, and it was the first Swedish castle built with thickset circular towers able to withstand cannon fire. The lakes around it were part of the defence, obstacles to any Russian advance. The keep was finished in 1485 and the outer walls by 1495.