They are not places of the exterior world. They are creations within us.
We can choose to be at peace and experience Nirvana here right now in this moment or we can create our own internal ‘hell’ or Hades within us.
The mind will create hell if we allow it and become our thoughts and the heart and consciousness will bring ‘heaven’, joy, awareness, life, energy and all things that we associate with bliss and a Nirvana.
We have the choice what we experience in every moment. We always have our own Nirvana and we create our own hell if we choose the suffering of the mind.