The Salpa Line is a massive line of defensive fortifications approximately 1200 km long that was built in 1940-41 and in 1944 in order to defend the Eastern border of Finland.
The Salpa Line Museum in Miehikkälä is a museum on military history established in 1987 displaying the history of fortification works of the Salpa Line. The permanent exhibition of the museum consists of the exhibition and multimedia shows at the museum cafeteria and of guided tours to the fortifications on the outdoor museum area.
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.