The Clava cairn is a type of Bronze Age circular chamber tomb cairn, named after the group of 3 cairns at Balnuaran of Clava, to the east of Inverness. There are about 50 cairns of this type in an area round about Inverness.
At Balnuaran of Clava itself there is a group of three Bronze Age cairns which lie close together in a line running north east to south west. The tombs at either end are of the passage grave sub-type. The central cairn is of the ring cairn sub-type, and uniquely has stone paths or causeways forming 'rays' radiating out from the platform round the kerbs to three of the standing stones. The cairns incorporate cup and ring mark stones, carved before they were built into the structures. The kerb stones are graded in size and selected for colour, so that the stones are larger and redder to the south west, and smaller and whiter to the north east. All these elements seem to have been constructed as one operation and indicate a complex design rather than ad hoc additions.
The ring round the northern Balnuaran of Clava cairn was measured and analysed by Professor Alexander Thom. He found that the ring was slightly egg-shaped with a complex geometry of circles and ellipses which could be set out around a central triangle, using sizes which are close to whole multiples of what he called the Megalithic yard. While the geometry of the shape is generally accepted, the Megalithic Yard is more controversial.
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.