Pierre Louis de Maupertuis and his expedition came to Aavasaksa in 1736-37 to conduct their measurements, having determined it a great place as a triangulation point when they were examining the shape of the Earth. To be able to see well enough to the next triangulation points, they needed an open view and thus demanded the trees to be cut down from the hilltop.
Pierre Louis de Maupertuis and the expedition of L'Académie Française that came here in mid 18th century to do their measurements. The Swedish astronomer Anders Celsius - who we are to thank for the Celsius thermometer - was also part of this expedition. Based on his measurements along Tornio River, Maupertuis managed to prove that the Earth is flattened near the poles.
Friedrich von Struve had the triangulation points marked permanently. Aavasaksa is part of the Struve Geodetic Arc which is on the Unesco World Heritage list, as one of the six protected such points in Finland. Struve was also measuring the shape of the earth and he came to Aavasaksa in 1845. The triangulation point is on the highest point of Aavasaksa, at 242 meters above sea level, which is right under the observation tower.