Michalovice castle is located near the Jizera river, about 3 kilometres northwest of the town of Mladá Boleslav.
The ruins of the early Gothic Michalovice castle stands on the right bank of the Jizera river. It was built by members of the Markvartice family during the last quarter of the 13th century to replace an earlier manor house. It was left to decay already in the 15th century. In the 19th century the ruins of the castle were sacked by treasure hunters, and now only the look-out tower remains.
The robust cylindrical leaning tower is the reason the castle has often been called the tub of Michalovice ('Michalovická Putna').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.