The Baltic Sea is the largest expanse of brackish water in the world. The rivers and rainwater are the reasons that the water of the relatively shallow sea is brackish, a mixture of fresh water and saline seawater. There are about sixty rivers draining into the Baltic Sea. A similar spit lies to the northeast it is the 98 km long Curonian Spit, a sand-dune spit between Kaliningrad Oblast and Lithuania that separates the Curonian Lagoon from the Baltic Sea. The Gulf of Gdańsk, also known as Gdańsk Bay, includes the Bay of Puck and the brackish water Vistula Lagoon, which is separated from the Gdańsk Bay by the Vistula Spit, a peninsular sand stretch.

The Gulf of Riga is a bay between Latvia and Estonia. The Gulf of Bothnia between Finland's west coast and Sweden's east coast is the northernmost arm of the Baltic Sea, the shallow Gulf of Finland between Finland and Estonia is the easternmost. There are nine countries with a shoreline at the Baltic Sea: Denmark, Germany, Poland, Russia (at the Gulf of Finland, and the Russian exclave of Kaliningrad Oblast), Lithuania, Latvia, Estonia, Finland, and Sweden. Approximately 85 million people live in the larger Baltic Sea region and use the sea for various purposes. The Baltic Sea (including the Gulf of Bothnia and the Gulf of Finland) covers an area of 377,000 km2 (146,000 sq mi), making it somewhat larger than Germany or slightly smaller than the US state of Montana. The Baltic Sea is known by a variety of names the Germans call it Ostsee (East Sea), the Swedish Östersjön, in Danish it's Østersøen, in Russia, it is known as Baltiyskoye More, in Finland as Itämeri, for the Polish people it is Morze Bałtyckie, in Lithuania, they call it Baltijos jūra and in Estonia, the 'East Sea' is known as Läänemeri (West Sea).īathymetry of the Baltic Sea map shows the ocean is in large parts quite shallow (light blue). In the 13th to the 15th century, the region was one of the main playgrounds and the commercial core of the Hanseatic League (Hanse), a confederation of merchants and city unions that became an economic and political power in Northern Europe. Today, the Baltic sea is connected to the North Sea (a branch of the Atlantic Ocean itself) via the Øresund Channel and the Kattegat and Skagerrak Straits, enabling Vikings of past times just as cruise ships of today to roam the seas for business. Some thousand years later, the sea became an arm of the Atlantic Ocean and a popular tourist destination. The lake's waters were the remains of several stages of the retreat of the melting Scandinavian ice sheet following the last glacial period we all know as the Ice Age. Nobody knows what the sea was called then, but scholars of today named it the Ancylus Lake. Ten thousand years ago, the waters we now know as the Baltic Sea were actually a vast inland sea, with only a few connections to the Atlantic Ocean through two or three rivers.

The Øresund Bridge, a rail and highway bridge over the Øresund, connects Denmark's capital Copenhagen with the Swedish mainland near Malmö.

World port map