Struve geodetic arc is part of the history of science and technology. It’s an UNESCO World Heritage feature that’s located in ten countries stretching from Arctic Ocean to Black Ocean. The countries are Norway, Sweden, Finland, Russia, Estonia, Latvia, Lithuania, Belarus, Moldova and Ukraine. German-born Russian scientist Friedrich Georg Wilhelm von Struve used it during 1816 – 1855 to determine the Earth’s size and shape using triangulation. The arc had 265 measurement points spanning over 2800 km. 34 of them are UNESCO protected sites since 2005.
Six of them are located in Finland, one of them in Tornikallio, at coordinates 60°42′17″N 26°00′12″E . It was marked by a drill hole in the bedrock and has been one of the basic points of surveying in Finland ever since.
The photo was taken by Minna of Minor Postcards during summer of 2017 at the measuring point. Even though people still go there to see the view, nature is reclaiming the area and there are trees growing all around the spot.