When did you last hear of the Sudety Mountains? Could you even begin to place them on a map?

There are some mountain ranges which are easily defined. The Sudety Mountains are not among them. The great arc of the Alps, sweeping from the Riviera north through Savoy into Switzerland and east through Austria almost to the Danube, lends itself to neat cartographic depiction. Much the same applies to the Pyrenees. We could all probably sketch in the location of the Alps and the Pyrenees on an outline map of Europe.

But other mountain ranges are more complex. The Eastern Ghats in India are patchy and discontinuous. The Drakensberg in southern Africa, more a mighty escarpment than a true mountain range, is not everywhere as mighty as it might be.