Black Sea–Caspian Steppe language and the Northeast Caucasian languages are related to Hurrian and Urartian. This implies that the mountaineers of the Caucasus have been in their present location for a very long time. According to the most common theory the Indo-European languages originated on the steppes north of the Caucasus and Black Sea. Some time before 3000 BC the Maikop culture appeared in Circassia and Kabardia. It is noted for its excellent gold and silver work. North on the steppe was the Yamnaya culture which was probably Indo-European. Around 1000 BC there was a bronze-age Koban culture in the Kabardian area which
Black Sea joins the world ocean. When this hydrological link is not present, the Black Sea is an endorheic basin, operating independently of the global ocean system, like the Caspian Sea for example. Currently the Black Sea water level is relatively high, thus water is being exchanged with the Mediterranean. The Turkish Straits connect the Black Sea with the Aegean Sea, and comprise the Bosphorus, the Sea of Marmara and the Dardanelles. The International Hydrographic Organization defines the limits of the Black Sea as follows: Current names of the sea are usually equivalents of the English name "Black Sea", including these given