The castle of Arena was built by the Norman king Roger I the 11th century, to protect the pass of Berra and to defend the dominions on the Tyrrhenian side of the greenhouses against the risk of potential attacks from the eastern side, where Byzantines and Arabs had important positions.
The administrative and military control of the feud of Arena was entrusted to the Conclubet family, which for over 600 years was confirmed in power by the different dominations that succeeded one another in Calabria ultra, to which the Acquaviva dukes took over in the sixteenth century.
The ruins of the castle, substantially destroyed by the earthquake of 1783, preserve the Norman architectural structure, with large perimeter walls and the main building in the shape of a quadrilateral.
At the corners of the quadrilateral there are four partially preserved towers, belonging to different periods during which the castle underwent various technical – defensive adaptations.
Thus, in the Angevin age, the original quadrangular towers with smooth shoe of the Norman tradition, were replaced on the eastern side by high towers with a circular base and grooved shoe, the latter aimed at increasing the results of the so-called “plumbing defense” technique. increasing the range and lethality of the projectiles launched from the walls. Just the grooved shoe base is a constructive rarity since the typical Angevin tower had a smooth shoe.
On the western side, the Norman towers were modified only in the Aragonese period, when the development of artillery made it necessary to lower and strengthen them.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.