Risbebjerg is an archeological site containing both the remains of a Neolithic sun temple and Iron Age earthworks. Bordered by the Øleådalen valley, the site is marked by Iron Age earthworks consisting of semicircular ramparts 3 metres high and a dry ditch 2 metres deep, dating back some 2,000 years. There are also remains of a number of 5,000-year-old woodhenges, one of which has been recreated with stumps of wood in the original holes, giving an impression of the size of the ancient site. An observation tower provides information and views over the historic area.
The site was discovered in 1897, leading to finds near a spring of six flint axes and four flint chisels from the mid-Neolithic. The following year, a further 13 flint axes and two chisels were found, making it one of the principal sites for finds of flint axes and chisels. The fact that the finds were made near a spring indicated that the site had religious significance.
The site contains a number of ancient wooden circles from about 2,800 BC. Traces of the original wooden poles have been found and recently marked out with stumps of wood. From the clay pieces, burnt flint and burnt bones found on the site, it has been suggested that the circles may have served as a sun temple. They apparently supported a clay-covered platform, accessed by a flight of steps, on which experts believe fires could have been lit, possibly for sacrifices. Clay disks with ancient sun symbols have also been found, ritually buried under the poles. It appears as if the wooden circles were constructed over three separate periods.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.