The Ural Mountains and the Caucasus Mountains separate Europe from Asia. These two mountain ranges form a distinct border between Europe and Asia.
The idea of Europe as a geographical entity has always been somewhat indistinct. Its transition into Asia is permitted by a continuous land mass. To ease this distinction, geographers divide Europe at its highest points, which are the mountain ranges. The boundary between Europe and Asia is considered to proceed south from the Arctic Ocean along the Ural Mountains and then along the tops of the Caucasus Mountains. The Volga river is considered to be the separation between the European and Asian parts of these ranges.