Although precise definitions vary, the South Pennines mostly cover the Pennine area between the Yorkshire Dales, Bowlands Fells and Peak District. It is separated from the Yorkshire Dales to the north by the Aire Gap, the Bowland Fells to the north west by the Ribble Valley and the Peak District to the south by the Chew, Colne and Holme Valleys. The West Lancashire Coastal Plain and Greater Manchester conurbation are both to the west while the West Yorkshire conurbation is to the east.