Finland–Sweden border border continues south into the northern Baltic Sea to a point where it meets the zone border of Estonia. The tripoint between the economic zones is defined by a treaty signed in 2001. The Finnish–Swedish border was created in 1809 by the Treaty of Fredrikshamn, as Sweden ceded Finland over to Russia. The course of the border was described in the fifth article of the treaty, without great detail. The borders were agreed to be the Sea of Åland, the Gulf of Bothnia, and the rivers Tornionjoki and Muonionjoki. Islands in the sea belonged to whichever country was the nearest
Poland–Russia border Soviet Union (USSR), shaped during the Polish-Soviet War, and confirmed at the Treaty of Riga at the line Dzisna-Dokshytsy-Słucz-Korets-Ostroh-Zbrucz. That border was long. Following World War II, the new border (see territorial changes of Poland immediately after World War II) was drawn between the People's Republic of Poland and the USSR. The new Polish-Soviet border was long at first, and subject to a minor modification in the 1951 Polish–Soviet territorial exchange, which reduced the border length to . The modern border between Poland and Russia is regulated by a number of legal documents, many of them dating to the times