Moeche Castle was built in the 14th century by the Andrades Family. It has an octogonal groundplan, and its walls are 10 m high and 3 m thick. Its gatekeep is 18 m tall and it is the only part of the castle protecting its walls from the outside. It was under siege and taken by the Irmandinos uprising.
The Moeche Castle has been restored recently, but in order to visit the interior of the castle, you'll have to request the keys from the local town hall.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.