Struve Geodetic Arc

Finland, Norway, Russia, Ukraine, Maldova, Estonia, Belarus, Sweden, Latvia, Lithuania 

Missing:  Latvia, Lithuania

The Struve Arc is a chain of survey triangulations stretching from Hammerfest in Norway to the Black Sea, through 10 countries and over 2,820 km. These are points of a survey, carried out between 1816 and 1855 by the astronomer Friedrich Georg Wilhelm Struve, which represented the first accurate measuring of a long segment of a meridian. This helped to establish the exact size and shape of the planet and marked an important step in the development of earth sciences and topographic mapping. It is an extraordinary example of scientific collaboration among scientists from different countries, and of collaboration between monarchs for a scientific cause. The original arc consisted of 258 main triangles with 265 main station points. The listed site includes 34 of the original station points, with different markings, i.e. a drilled hole in rock, iron cross, cairns, or built obelisks. Source whc.unesco.org

Moldova: Rudi Village

Thanks to Mr Tiago for send this this card from Portugal.

Estonia: Tartu Observatory

Thanks to Mr Patrik.

Norway: Hammerfest

Thanks to Jo Heggland.

Finland: Oravivuori

Thanks to Ms Sini

Finland: Alatornion Kirkko Church

Thanks to Ms Sini

Russia: Gogland Island

Thanks to Mr Vadim

Ukraine: Staraya Nekrasovka

Thanks to Ms Olesya

Belarus: Ossownitza

Thanks to Ms Katya

Belarus: Various Points

Thanks to Ms Lisa.

Sweden: Perra Vaara, Haparanda

Thanks to Ms Merja Deb. Bottom row (L-R) third box is Struve Geodetic Arc.