Mountains and hills of England the land rises to form the Cheviot Hills, which extend into Scotland and could probably be considered part of the Southern Uplands. They are included in Northumberland National Park, along with Kielder Water and the Kielder Forest. The North Pennines (an Area of Outstanding Natural Beauty, or AONB) lie south of Hadrian's Wall, and east of the Lake District, from which they are separated by the Eden Valley. These are younger rocks, mostly Carboniferous limestone, and the mountains are characterised by shallower slopes covered with moorland vegetation, culminating in Cross Fell at . South of this, the main line of
North–South divide (England) in Yorkshire and Alderley Edge, Wilmslow, Bowdon and Chester in Cheshire. On the other hand, geographically southern areas such as the Isle of Thanet in Kent have struggled with the same industrial decline as parts of the north. Cornwall, many London boroughs such as Hackney and Haringey and southern towns like Luton are other anomalies to the North-South divide with poor health and education. This has led some commentators to suggest that other divisions, such as class or ethnicity might be more important. The Economist claims that one of the main causes of the divide was the migration of young