"That area west of Raleigh, NC, is called the Piedmont."
The Piedmont (named after a similar region in Italy) is actually the base of an old mountain chain, that runs in a line from South of new york city to Georgia. Something about the geology of the worn down mountain base gives it its characteristics, roling hills, red clay soil, and folage that is greener than anyplace else.
In my home town of Washington DC, the edge of the Piedmont runs right through the middle of town (roughly down Georgia Avenue). So half of the city is in the Piedmont and half at the edge of the Coastal plain. Going to work, I used to cross from the P to the C and you copuld really tell the difference. The land got flat, and the trees lost that bright green color. Of course, all of the poshy neighborhoods had developed on the Piedmont side (the grass really IS greener there).
I know all this because Arthur Godfry's son (remember AG?) wrote a book called "The Piedmont". Probably out of print now.