This magnificent monument is located in the eastern part of Sweden. It is called as Kalmar castle as it is situated on the small peninsula of the Kalmar straight. The whole castle was built way back in the 14th century and due to the erosion and different destructions by the time and wars, it had to be rebuilt again after two centuries. It stands near the harbor and due to this people refer to it as the ‘Key to the Kingdom’. This castle has time and again served as a prominent defense from the Danes attack due to its location on the border of Denmark.