Kalmar Castle

Kalmar Castle (Swedish: Kalmar slott) is a castle in Kalmar, in the province of Småland, Sweden. Its origins date to the 12th century, with a defensive tower constructed on the site around 1180. Owing to its strategic location near the former border with Denmark, the castle was historically known as Rikets nyckel ("the Key to the Kingdom"). During the 16th century, the Vasa kings transformed the medieval fortress into a Renaissance palace; today, it is described by Statens fastighetsverk as the best-preserved Renaissance castle in the Nordic countries. In 1397, the castle was the site of the formation of the Kalmar Union, which united Denmark, Norway and Sweden under a common monarch.