Adavere manor was first mentioned in the second half of the 17th century. In the 16th and 17th centuries Adavere was under the rule of Põltsamaa, which as the most important town in Central Estonia administered all of the surrounding land and villages. On maps dating from 1682 Adavere is already marked as a manor. Its massive slate main building was constructed from 1892-1893. The complex also includes auxiliary buildings erected in the late 19th century - a workers' cottage and a barn and drying shed. The park (dating from the 1740s) was one of the grandest in Estonia in its day, although little remains of this today. The Art Nouveau artworks in the main building were restored in 2000. Today the building is home to Adavere School.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.