, located near the site of Kalmar's medieval
harbor, has played a crucial part in Swedish
history since its initial construction as a fortified tower in the 12th century. King Magnus Ladulås
ordered the construction of a fortress around the tower in the 1280s
, and was further expanded in the centuries that followed.
One of the most significant political events took place at Kalmar Castle in 1397, when the Kalmar Union was formed - a union of Denmark, Norway and Sweden, organized by Queen Margaret I of Denmark.
The fortress was improved during the 16th century under the direction of King Gustav Vasa and his sons Eric XIV and John III, who turned the medieval fortress into a castle fit for a renaissance king. Today, it is one of Sweden's best preserved renaissance castles.