The typical Galician noble fortress in Castro Caldelas with medieval origins has been splendidly conserved and restored and today functions as a library, cultural centre and exhibition venue.
The castle originally belonged to the House of the Counts of Lemos, and became part of the House of Alba in the 18th century. It was built in the 14th century as a fortress with a purely military function, and was renovated in the 16th century and converted into a palatial residence.Its floor plan is in the shape of an irregular polygon, as it adapts to the hill on which it stands. It comprises several parts or buildings, of which the rectangular keep and the clock tower are the oldest. Other surviving elements include the bailey, sections of the defensive wall, three square towers, the administrator's house, the palace (containing the library, a museum about the castle and other rooms), the interior sentry walk and the outer moat.
The location of the castle, on top of a mountain, also provides some panoramic views of the valleys below and it is easy to appreciate how impenetrable this town must have seemed to past aggressors.
You enter the castle (free of charge) through the main gateway and once inside you have unlimited access to all areas including the battlements.References:
First record of Kastelholma (or Kastelholm) castle is from the year 1388 in the contract of Queen Margaret I of Denmark, where a large portion of the inheritance of Bo Jonsson Grip was given to the queen. The heyday of the castle was in the 15th and 16th centuries when it was administrated by Danish and Swedish kings and stewards of the realms. Kastelhoma was expanded and enhanced several times.
In the end of 16th century castle was owned by the previous queen Catherine Jagellon (Stenbock), an enemy of the King of Sweden Eric XIV. King Eric conquered Kastelholma in 1599 and all defending officers were taken to Turku and executed. The castle was damaged under the siege and it took 30 years to renovate it.
In 1634 Åland was joined with the County of Åbo and Björneborg and Kastelholma lost its administrative status.