The castle was began to be built at the XII century, and in 1397 it was the stage for a major political event when the Kalmar Union was formed. That event was about the union of Denmark (that included Iceland and Greenland), Sweden (that included Finland and some possessions in the north of Germany, Poland and Baltic countries) and Norway with the capital in Copenhagen. The union was broke by Sweden in 1520.
Later on in 1611 there was a war between Sweden and Denmark-Norway (known as the Kalmar war) in which Sweden lost and the castle was nearly destroyed. Afterwards there was a major reconstruction work, and today the castle looks like a nice renaissance palace that can be visited.
Photo taken from an artificial island built in the Baltic sea part of the industrial/harbour park.
Kalmar – Sweden