The Gulf of Finland (Finnish: Suomenlahti, Russian: Финский залив, Finskiy zaliv, Swedish: Finska viken, Estonian: Soome laht) is the easternmost arm of the Baltic Sea that extends between Finland (to the north) and Estonia (to the south) all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn. The eastern parts of the Gulf of Finland belong to Russia and some of Russia's most important oil harbours are located farthest in, near Saint Petersburg (including Primorsk). As the seaway to Saint Petersburg, the Gulf of Finland has been and continues to be of considerable strategic importance to Russia. Some of the environmental problems affecting the Baltic Sea are at their most pronounced in the shallow, cul-de-sac gulf.