Kastelholm Castle was first mentioned in chronicles in 1388 as "The House Kastelholm." The exact date of the founding of the castle, however, is unknown. Since the end of the XV century, the castle was the administrative center of the archipelago and has played an important strategic role, as well as a hunting castle of the Swedish queen.

In the present form the castle is a complex architectural complex to build and expand during the period from the end of the XIV to the middle of XVII century. In 1745, in the castle there was a devastating fire. Only in the twentieth century, it was restored and opened to the public.

Near the castle two museums are open. One - State prison museum Vita Björn, located in an old prison building. Vtooy - open-air museum Jan Karlsgordena, where you can see more than twenty Aland traditional houses and mills of the XIX century. In the old inn visitors are treated to national dishes.