Obviously there's Pinehurst/Southern Pines.
Also the RTP/triangle area, Raleigh and Chapel Hill.
The triad west of the RTP (Greensboro/W-S) and Asheville and Nags Head.
What else am I missing?
Pinehurst/SP - a more gentrified quieter smaller version of MB without the beach.
Triangle Area - decent courses, some university courses, spread out.
Nags Head - resort courses.
Triad - decent number of courses, good bang for the buck.
Ashville - not many courses but nice granola crunchy area to visit.
Wilmington - most of the courses seem like they're private. Do they let non members play?
Brunswick County, NC, just across the state border from Myrtle Beach SC must qualify as a "golf cluster". The Villages of Shallotte, Calabash etc have dozens of golf courses in a small geographic area: Rivers Edge, 27 holes at Carolina National, St James Plantation (4 courses), Leopards Chase, Tigers Eye, Panthers Run and Lions Paw, Oyster Bay, 3 courses at Sea Trail, 27 holes at Thistle, Farmstead, Crow Creek, Brunswick Plantation, Lockwood, Bald Head Island, 27 holes at Sandpiper, two courses at the Pearl...