The first defensive construction, a round tower, was built on Kalmarsund in the 12th century concurrently with the harbour. At the end of the 13th century King Magnus Ladulås had a new fortress built with a curtain wall, round corner towers and two square gatehouses surrounding the original tower. Located near the site of Kalmar's medieval harbor, it has played a crucial part in Swedish history since its initial construction as a fortified tower in the 12th century.
One of the most significant political events in Scandinavia 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. During the Swedish rebellion against Denmark in1520, the fortress was commanded by Anna Eriksdotter.
The fortress was improved during the 16th century under the direction of King Gustav I and his sons King Eric XIV and King John III, who turned the medieval fortress into a castle fit for a renaissance king. Kalmar Castle suffered heavy damage during the Kalmar War of 1611-13 and was badly damaged by a fire in 1642. Repairs were begun but from the end of the seventeenth century the castle was allowed to fall into disrepair.
In 1856, architect Fredrik Wilhelm Scholander (1816 - 1881) initiated restoration work at Kalmar Castle. His pupil Helgo Zettervall continued restoring Kalmar Castle in the 1880s. Architect Carl Möller drew up the plans and other documents. The work began in 1885 and by 1891 the castle had gained the silhouette it bears today. In 1919 professor Martin Olsson was charged with the continuing restoration of earthworks, the moat, the bridge and the drawbridge. Work continued until 1941, when the castle was once more surrounded by water. Today, it is one of Sweden's best preserved renaissance castles and is open to the public.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.