Samuel's Fortress in the old town of Ohrid was built during the rule of Tsar at the turn of the 11th century. Today, 18 towers and four gates still remain from the original structure. With its strategic location overlooking the town and the lake, it provides an ideal place for taking in the whole panorama of Ohrid and its surroundings. It was heavily restored in 2003 with the addition of entirely new battlements where none had survived.
According to recent excavations by Macedonian archaeologists, it was contended that this fortress was built on the place of an earlier fortification, dated to the 4th century BC, which was probably built by King Philip II of Macedon.
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.