Mediterranean Sea
The Mediterranean Sea separates Europe from Africa and is an extension of the Atlantic Ocean. This sea is connected to the rest of the Atlantic by the Straits of Gibraltar, and connects to the Black Sea naturally via the Bosporus. Another man made connection, through the Suez Canal, joins the Mediterranean Sea to the Red Sea (an extension of the Indian Ocean). The Mediterranean Sea is almost completely enclosed by land. Only a narrow channel prevents the sea from being separated from the Atlantic. This means that the Mediterranean's currents and weather are less severe than the Atlantic's, making navigation on easier. In addition, the sea's influence makes the climates of the regions surrounding it warmer and wetter.
For these reasons, the Mediterranean was an excellent environment for the development of early civilizations. The Phoenicians, Greeks, Egyptians, and Romans all lived on the shores of the Mediterranean and used it for trade. Today it is still an important trade route, and is very important in the geography of both Southern Europe and North Africa.