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
Cheviot Hills country' and hence there is a general right to roam over it as prescribed in the Countryside and Rights of Way Act 2000. Traditional rights of access in Scotland, bolstered by the Land Reform (Scotland) Act 2003, provide for similar access for the public to the north of the border. In addition, a sparse network of public bridleways and footpaths stretches around the area, often providing useful means of access from the lower ground onto the open hills. The northernmost leg of the Pennine Way runs from Byrness in England to Kirk Yetholm in Scotland. It is the longest, and