Complex sentence: The northern part between its source and Tebay is called Lunesdale, which is followed by the spectacular Lune Gorge through which both the M6 motorway and the West Coast Main Railway Line run.
Split into simpler sentences: The northern part between its source and Tebay is called Lunesdale. Below this is the spectacular Lune Gorge through which both the M6 motorway and the West Coast Main Railway Line run.