An in-depth report on the Iso Mahonsaari island find will be featured in the upcoming issue of “Tähdet ja avaruus” (Stars and Space) magazine of the Ursa Astronomical Association.
The enclosure measures 25 x 18 metres. Typical to such structures, its outlines are traced with earth mounds, and there are piles of stones around it. Depressions have also been dug in the ground.
The axel of the complex is aligned with winter solstice sunrise and summer solstice sunset – a design shared with the Karnak temple complex in Egypt and Britain's Stonehenge.
Churches for giants
Called “jätinkirkot”’ or “giants’ churches” in Ostrobothnian tradition, such structures are usually circular or rectangular, and date back to between 3,000 and 1,800 BCE.
All 50 such structures so far found in Finland are located near the shores of the Bay of Bothnia, in Ostrobothnia.
The function for the buildings remains under speculation. For one, they are believed to have been used for religious practice. The astronomical accuracy of the complexes also points to agricultural purposes, as these could have aided in accurate observation of the seasons.
Most likely built by late Stone Age hunter-gatherers for whom seals were important prey, the structures are located by waters – the Baltic, and a great inland lake – which would have had seal populations. This has led some researches to link the Neolithic structures also with seal hunting.