Beaghmore is a complex of early Bronze Age megalithic features, stone circles and cairns. The site was discovered by George Barnett in the late 1930s during peat cutting when 1,269 stones were uncovered, and partially excavated in 1945–1949 when it was taken into state care. It was also excavated again in 1965. Hearths and deposits of flint tools were discovered and have been carbon dated to 2900-2600BC. Several of the stone rows run over the tumbled walls of field structures which also date from the Neolithic period. Excavation of one of the cairns revealed a polished porcellanite axe, which may have originated from the Tievebulliagh axe factory, some 70 miles away in County Antrim. The largest cairn featured a central pit containing an oak branch.
There are seven low stone circles of different sizes, six of which are paired, twelve cairns and ten stone rows. The circles are between 10 and 20m in diameter, and are associated with earlier burial cairns and alignments of stone rows lead towards them. The stones are small with few more than 0.5m in height and the circles are distorted, suggesting they are related to kerbs surrounding some megalithic tombs. A typical feature of the stone rows is a high and low arrangement where short rows of tall stones run beside much longer rows of small stones. The stone rows radiate from the circles in a roughly north-east direction.
References:Towering 52 meters above the sea, Bengtskär lighthouse is the tallest one in Scandinavia. The building started in in 1905 after the shipwreck of S/S Helsingfors and was completed in 1906. The lighthouse was designed by architect Florentin Granholm. On December a special petrol lantern, designed and built in Paris, was brought to Bengtskär and installed atop the tower.
German fleet bombarded Bengstkär in the First World War in 1914. Since the Gulf of Finland was heavily mined, it was not until 1919 that the surrounding seas were declared safe for shipping, that the light was lit again.
After the war the military value of Bengtskär increased as part of the defence system of independent Finland. In Second World War (1941) Soviet Union made a suprise attack to island. After a bloody battle, the small Finnish garrison emerged victorious. Intermittent repairs to the facility continued during the post-war period.