All Saints Church is surrounded by a castle-wall-type barrier - by the wall of the former cemetery. The residents of the valley of the Tettye river built a one-navy church here as early as the 13th century. The originally Romanesque style All Saints Church was reconstructed in the 15th century in Gothic style. The exterior is simple, while a short tower stands on the triangular pediment of the main façade. The interior is mostly 18th century Baroques style. During the Turkish occupation this was the only church that still belonged to the Christians. It was used jointly by Catholics, Calvinists and Unitarians. This is where the famous religious dispute of the Calvinist Máté Skaricza and the Unitarian György Válaszúti took place in 1588.
The church became Unitarian by the mid-17th century, the Catholics only managed to regain it in 1664. Following this period, it was under Jesuit management until 1704. At this time it was reconstructed to be a three-nave church, this is when the little tower was added. On the south side of the cemetery, protected by stone wall, 18th-19th century graves, on the north, Baroques graves can be found.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.