Daugava or Western Dvina is a large river rising in the Valdai Hills of Russia that flows through Belarus then Latvia into the Gulf of Riga of the Baltic Sea. It rises close to the source of the Volga. Its length is 1,020 km, of which 325 km are in Russia. It is a westward-flowing river, tracing out a great curve towards its south which means it passes through northern Belarus.
Latvia's capital, Riga bridges the estuary four times, lying on both banks, the city centre being 15 kilometres from the mouth and being a significant port.
Wikipedia https://en.wikipedia.org/wiki/Daugava
Coordinates 56°33'19.106" N 25°42'48.655" E