A three-towered castle was established in the fifteenth century, specifically in the year 1477, and was built on an island located between two lakes in the city to secure protection against Russian attacks coming from the east, and was built by Lord Erik Axelsson Tott, and it was the first Finnish castle Forged with circular towers qualified to withstand cannon fire. Today, the castle has a huge theater where opera performances are held, a fine restaurant and an amazing museum that tells the history of the city.