Struve Geodetic Arc

The Struve Geodetic Arc is a chain of 34 survey triangulations stretching from the Arctic Ocean to the Black Sea. The best-known points in Finland are Oravivuori point in Jyväskylä and Aavasaksa point in Ylitornio. The site was added to the UNESCO World Heritage List in 2005.

Six of the station points on the World Heritage List are located in Finland: the Stuorrahanoaivi point in Enontekiö (completed in 1850), Aavasaksa point in Ylitornio (1845), Alatornio Church (1842), Oravivuori point in Jyväskylä (1834), Porlammi point in Lapinjärvi (1833) and the Mustaviiri point in Pyhtää (1833).

The Struve Geodetic Arc, named after the German astronomer Friedrich George Wilhelm Struve, who created the chain in the early 19th century, represents the scientific and technological cultural heritage of its era. He attempted to determine the shape and size of the Earth with the method of triangulation. Triangulation is based on observations made of the angles of networks of triangles, which is helpful in surveying certain areas. GPS devices have since replaced the traditional method of triangulation.

The arc consists of 258 of main triangles and 265 main station points from Norway to Ukraine through ten countries, spanning 2,820 kilometres. The cross-border Struve Geodetic Arc is the first World Heritage Site to range over this many countries.

The Struve station points in Finland are maintained by the National Land Survey of Finland. Most of the points are open to visitors throughout the year.