Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. Europe, in particular ancient Greece, was the birthplace of Western civilization. The fall of the Western Roman Empire during the Migration Period marked the end of ancient history and the beginning of an era known as the Middle Ages. Renaissance Humanism, exploration, art, and science led to the modern era.