10 most difficult Baltic Sea riddles

Vistula is the longest of the Baltic Sea affluents, but its mean discharge of 1080 m3/s is less than half of Neva (2500 m3/s). Other major Baltic Sea effluents are Daugawa nad Neman (both 678 m3/s).

It is an archipelago at the entrance to the Gulf of Bothnia in the Baltic Sea belonging to Finland. It is autonomous, demilitarised and is the only monolingual Swedish-speaking region in Finland, hence the similarity of the flag above to the Swedish one.

The Baltic Sea is one of the largest brackish inland seas by area, and occupies a basin formed by glacial erosion during the last few ice ages. It is about 1,600 km (990 mi) long, an average of 193 km (120 mi) wide, and an average of 55 metres (180 ft) deep. The maximum depth is 459 m (1,506 ft).The current course of the shoreline was formed about 2 thousand years ago.

Baltic Porter is a very high alcohol, sweet, robust porter that originated in the Baltic states. Baltic Porter reflects both the character of original British Porters and the character of sweeter, highly alcoholic Russian Imperial Stouts.

The area of the Danish island of Zealand is 7031 km². Swedish Gotland has an area of 3144 km², Bornhom Denmark 588 km², and Usedom 445 km².

In all Germanic languages except English the Baltic Sea is called "East Sea" - this includes German (Ostsee), Dutch (Oostzee) and all Scandinavian languages. The name has been used since the Viking age, and was also adopted (through Swedish) into Finnish language, disregarding the geography (the sea is west of Finland).

A number of rivers from both countries flow into the gulf. As a result, a salinity gradient exists from north to south. In the south the water is the normal brackish water of the Baltic Sea, but in the north, the salinity is so low, that one can no longer taste the salt in the water and many freshwater fish thrive in it.

The Baltic Sea is one of the youngest seas in the world. It was formed after the last ice age as an ice-lake, which later turned into a sea.

Estonian belongs to the Finnic branch of the Uralic language family. Estonian and Finnish are not Indo-European languages, hence Latvian is more closely related to English, than to Estonian.

The average depth of the Baltic Sea is 52.3 meters. This sea is divided in 3 large basins: Gulf of Bothnia with the maximal depth of 294 meters, Gotland Basin - 459 meters deep in its lowest point and the Bornholm Basin with the depth of 105 meters.