Sønderborg Castle

Visit the historic castle in Sønderborg, the museum and the beautiful surroundings.

Sønderborg Castle was built about 1170 on the island of Als, and the castle has filled various functions over the centuries. 

During the 14th and 15th centuries, it became a heavily fortified citadel owned alternately by the Danish kings and the dukes of South Jutland.

The castle converted to a prison

In the middle of the 1500 century, the castle had the function as a prison for the deposed King Christian II.

The castle has been rebuilt more times to a more Baroque style, and the chapel is the best preserved Lutheran chapel from the time of the Reformation in Europe.

Later between 1864 and 1919 during the Napoleonic War and the Danish-German Wars, Sønderborg Castle served as a military hospital.

Sønderborg Castle became Danish

By the referendum in 1920, the northern part of South Jutland including Sønderborg and the castle became Danish.

Since 1908 the castle has been converted into a museum with emphasis on the more recent history of South Jutland.


Sønderborg Castle
Sønderbro 1
6400 Sønderborg
Sønderborg, South Jutland
+45 74422539

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  • Lattitude: 54.909055
  • Longitude: 9.773895