In the North West of England the main transmitter is Winter Hill based on the outskirts of Bolton. It is one of the countries more powerful Digital TV Transmitters. With coverage going from south lakes over to Morecambe blackpool southport down into Liverpool and into Cheshire as far south as Nantwich then over to the east side to the edge of the peak district and back up to Rochdale and through Rossendale valley and through Blackburn onto colne nelson and even as far as barnoldswick, and everything inbetween.
To summarise it is one big area although with a lot of hills and reception is bounced from relay stations offering a Freeview Lite service.
Other main transmitters serving the North West are Pendle Forest, Saddleworth and Lancaster these all provide a full Freeview service.