Besides estate and boundary maps, a set of little-known parish maps was created in the middle of the 18th century, with Central Finland well represented. A grandiose programme for the production of geographical maps was launched in Sweden-Finland at least in part inspired by a scientific expedition which worked in the River Tornio valley under the leadership of de Maupertuis, a Frenchman. In 1737-1747 and in 1748 surveying commissions operated in Finland, making maps of more than a hundred Finnish parishes on the scale 1:20 000. The area that was roughly mapped consists of parishes from the eastern border to Central Finland. The majority of the maps are kept in the Swedish state archives. Despite various efforts the maps have not been handed over to Finland. In Sweden there are parish maps dealing with nearly 100 Finnish parishes, whereas in the Finnish national archives these amount to 30.