The fishing village of Garrucha suffered at the hands of Berber pirates until the year 1766 when barracks were built at Escobetas, a provisional military building. In 1769, the castle was completed at a cost of 181,000 reais. The fort was designed by the architect Francisco Ruiz Garrido. After its construction, Garrucha began to grow.
It is of masonry construction in three section. The central portion is rectangular with rounded short sides. Attached to the right lateral side, there is a truncated pyramid shape with sloping walls. In its upper part, a parapet is pierced with loopholes. The main body is attached to the left side, of lower height, without openings. It is accessed by an external staircase and one tranche that attaches to the right side.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.