Possible Clues:

• By no means the first writer's venue for hill-walking!
• Region for hikers from north, during some change
• Chain fences round square
• Not one chain of mountains but another
• Backbone of England
• Brass covering northern hills
• Range of enclosures round square
• Not a chain in southern Europe but one in northern England
• Range in which writer figures
• The 'backbone of England'