The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Southern Europe and Anatolia, on the south by North Africa, and on the east by the Levant in West Asia. The Mediterranean has played a central role in the history of Western civilization. Geological evidence indicates that around 5.9 million years ago the Mediterranean was cut off from the Atlantic and was partly or completely desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago.

A sea is a large body of salty water. There are particular seas and the sea. The sea commonly refers to the ocean, the wider body of seawater. Particular seas are either marginal seas, second-order sections of the oceanic sea, or certain large, nearly landlocked bodies of water.