Kalmar has been around since ancient times and a castle has been around since the 12th century. It used to be a very important town, as it was on the historical border of Sweden and Denmark. The town has been burnt to the ground several times as wars and battles raged.
I doubt that any kid in any Scandinavian country has not heard of the Kalmar Union during history classes. At the end of the 17th century the importance of Kal,at diminished as new borders were drawn further south and some king founded a naval base at Karlskrona.
So one cannot pass by the castle. We joined a shorter guided tour, and it was fabulous. Jessica, the guide, really lived the part as we described the history, battles and living conditions during the castles’ heydays. Highly recommendable attraction. And if you’ve got small kids, they’ll love the extra activities as well.