The military Fort Venini in Oga was erected in the defense of the main alpine passes of the Alta Valtellina, and was built between 1908 and 1914 in the village of Dossaccio. The fort’s structure is decidedly massive and includes four armoured domes in steel where there were the cannons, that thanks to the particular orientation east-west, could rotate and defend all the valleys and the passes potentially subject to danger from the enemy.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.