sentences:  It stretches approximately from North Wales across Greater London to the Benelux states and along the German Rhineland, Southern Germany, Alsace in France in the west and Switzerland (Basel and Zürich) to Northern Italy (Milan) in the south.The French geographer Roger Brunet, who observed a division between "active" and "passive" spaces, developed the concept of a West European "backbone" in 1989.He made reference to an urban corridor of industry and services stretching from northern England to northern Italy.