Nirvana and the six heavens in the 31 realms
For any realm one can abide and say, "I am here."
Not so Nibbana/Nirvana, which is the cessation of identity view.


  MN1:124-146.23: nibbānaṃ nibbānato abhijānāti; ...
  
  MN1:124-146.23: They directly know extinguishment as extinguishment. But they don’t identify with extinguishment, they don’t identify regarding extinguishment, they don’t identify as extinguishment, they don’t identify that ‘extinguishment is mine’, they don’t take pleasure in extinguishment