Aavasaksanvaarantie 288, 95620 Ylitornio, Finland
The AVASAKSA point of the Struve Arc (currently spelled Aavasaksa, Aavasaksa) was marked by a central marker and two cross-shaped marks carved into the rock. In the 1920s, these markers were searched for by surveyors of the National Land Survey Service. At that time, they did not recognize them. During recent measurements, it was proven that the markers are located beneath the observation tower built in 1969 on the highest point of the hill. A modern triangulation point is installed on the tower, and the exact location of the arc point was determined by measurements confirming that it lies vertically below the position on the upper floor of the tower.
The chronicler of the de Maupertuis expedition recorded on Aavasaksa on July 8, 1736, the following: “Mount Aavasaksa is located in the most populated and beautiful part of the river: its channel, primarily to the south, extends for four or five leagues, is extremely wide, and represents the most suitable place we could wish for an excellent base, the ends of which would be visible from Whit-Taperi and Aavasaksa. This base could not be measured at any other time except winter over the ice; but it was suitable for fixing signals at its ends to connect it with triangles and conduct the necessary observations before winter arrived.”
Since Maupertuis’ time, Aavasaksa has been famed for its beauty and the midnight sun. Today, the territory of the Aavasaksa hill belongs to a nature conservation area owned by the Finnish state.
Pierre Louis Moreau de Maupertuis conducted an expedition to the Tornionlaakso valley in 1736-1737. De Maupertuis and Camus were the first to set up their instruments on the Aavasaksa hill. Since housing was available in Iltornio, Aavasaksa became the central location for the Maupertuis expedition’s measurements. Angular observations from Aavasaksa to Luppio and the baseline endpoint work were conducted at the end of August 1736. Unfortunately, their measurement points were not marked with permanent signs.
In the 19th century, the Aavasaksa hill was used for new measurements. Swanberg performed measurements at the beginning of the century, and later Selander and Lindhagen in connection with the Struve Arc measurements. According to documents, there were three marks at the point: one at the central point of the signal, the second 2.4 French feet west of the center, and the third 3.24 French feet east of the center. These points were not found during 20th-century research, partly because the rock bears many graffiti made by visitors who like to leave their initials as a memento on the rock. (* 1 French foot = 1.0654 English feet of that time).
Aavasaksa is located within a National Park, which was established in 1878 as one of the first in Finland and also in the world. In 1882, a hunting lodge of Tsar Alexander II was built here, whose rich interior has been restored and now serves as a museum. Recently, much attention has been paid to the development of the park, including the development of tourist infrastructure; many cafes and accommodation places have been built near the summit.
The Struve Arc, once known as the “Russian” and later the “Russo-Scandinavian Meridian Arc,” is one of UNESCO’s World Heritage monuments. The arc consists of 265 triangulation points, along which measurements were conducted from 1816 to 1852, allowing the precise determination of the Earth’s size and shape.
The reference points of this triangulation network were marked on the terrain in various ways: hollows carved into rocks, iron crosses, stone pyramids, or specially installed obelisks. Often, they were marked with sandstone bricks laid at the bottom of a pit; sometimes it was a granite cube with a cavity filled with lead, placed in a pit with cobblestones.
During the project to include the Struve Arc in the UNESCO list, which lasted 8 years, special search and geodetic work was carried out in each country to locate the original points. All information from all the countries of the Struve Arc was collected, structured, and standardized.
Not all original points were found during the special search and geodetic work carried out in recent years with active cooperation of scientists from interested countries, and many of them were found to be heavily damaged. Therefore, only the best-preserved points—34 in total—were included in the World Heritage site.
Sources:
http://www.gototrip.com/publications/geodezicheskaya-duga-struve
https://eurogeographics.org/wp-content/uploads/2018/04/1187.pdf
