Thanks to Annu from Finland.
The Struve Geodetic Arc is a chain of survey triangulations stretching from Hammerfest in Norway to the Black Sea, through ten countries and over 2,820 km, which yielded the first accurate measurement of a meridian.
In 2005, the chain was inscribed on the World Heritage List as a memorable ensemble of the chain made up of 34 commemorative plaques or built obelisks out of the original 265 main station points which are marked by drilled holes in rock, iron crosses, cairns, others.[1]
Measurement of the triangulation chain comprises 258 main triangles and 265 geodetic vertices. The northernmost point is located near Hammerfest in Norway and the southernmost point near the Black Sea in Ukraine. This inscription is located in ten countries, the most of any UNESCO World Heritage.
Marwa UNESCO WHS 