Europe has diverse geographic features including peninsulas, islands, seas, rivers and mountain ranges that help define its boundaries and regions. Major physical features include the Mediterranean Sea, Atlantic Ocean, Arctic Ocean, Ural Mountains and various peninsulas and islands. Rivers such as the Danube, Volga, Rhine and Seine flow across the continent draining into surrounding seas and oceans. Mountain ranges like the Alps, Pyrenees and Carpathians add relief to Europe's generally low-lying terrain. The continent has a variety of climates from Arctic to Mediterranean influenced by these physical elements.