Torre Fiorenzana is a tower house built in the late 12th century for the local de Grono family. The first mention of the family is 1219. They appear again in local records in 1286 and 1288. The Canon Bernardinus of Grono and the Provost Heinrich appear to have been the last male members of the family. By 1314 it was owned by the powerful Lords of Sax-Misox and a branch of the family inhabited it. In the 14th century they were signing documents as de Saco de Grono and in the 15th century were de Saco de Fiorenzana. According to tradition, in 1406 the powerful leader of the family, Albert von Sax, was murdered at Fiorenzana.
In the 16th century the tower was locally owned. The coat of arms of the Three Leagues was painted on it at that time. Over the following centuries, it was inhabited by a number of local families and today remains privately owned. The exterior was studied and repaired in 1978.
The castle is located in the center of Grono village. It is a five-story, rectangular tower. The crow-stepped gables along the roof were added by the Lords of Sax-Misox in the 14th century. The original high entrance was located on the third floor and is still visible.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.