Europe, conventionally one of the seven continents of the world. Although referred to as a continent, Europe is actually just the western fifth of the Eurasian land mass, which is made up primarily of Asia. Modern geographers generally describe the Ural Mountains, the Ural River, part of the Caspian Sea, and the Caucasus Mountains as forming the main boundary between Europe and Asia. The name Europe is perhaps derived from that of Europa, a consort of Zeus in Greek mythology, or possibly from Ereb, a Phoenician word for "sunset".