Borders. Europe is bordered by water on three sides. The western boundary is the Atlantic Ocean, the northern boundary is the Arctic Ocean, and the southern boundary includes the Mediterranean Sea and the Black Sea. These bodies of water provide clear boundaries but are themselves so distinct that Europeans living on the shores of one body of water have a radically different experience with the water than inhabitants living on a different body of water. The sheltered coasts and many natural harbors fostered sea-oriented, or maritime, economies that prospered during the late Renaissance and Reformation periods as naval developments turned the vast stretches of water into highways for trade and travel. The Ural Mountains, the Caspian Sea, and the Caucasus Mountains form an eastern frontier that is more ambiguous than the other borders.

Great European Plain. Between the low Ural Mountains and the relatively high...