How about a water park?
No idea how this is anymore, but 15 years ago it was a great place to go.
The zoo really is nice, as the state put funds in one central zoo rather than having city zoos competing.
There's NASCAR stuff like the HOF and speedway in Charlotte, a bit over an hour away.
Out doors, Hanging Rock or Pilot Mountain might be neat, but maybe you aren't looking for strenuous activities in down time.
ACC Hall of Champions is in Greensboro. No idea if that's worthwhile.