Many classical scholars misunderstand Hesiod when he speaks of Earth containing Tatarus.
Tartarus was the darkness, which may be the same as is called in the Bible ‘the darkness under the Earth’, or perhaps that was the waters beneath the earth. This is not to be confused with Night, a much vaster realm.
Tartarus is the place where the souls are lost and longing to return to life. They cannot do so, not through any fault of their own but because they are lost. Not in the sense of lost and damned forever. A concept peculiarly Christian in my life, though perhaps shared more widely than that. Lost because they are identifying with a former life they have lost and don’t know how to deal with the new situation.
As a result of this Tartarus is a place where the souls are wailing, and perhaps gnashing their teeth, or what passes for teeth amongst discarnate spirits.
But as to where this place is, well, it is necessary to expand the concept of Creation to include the revolution of the Sun about a given centre we call a cosmos. This is not to be mistaken for the Galaxy. The Sun is part of a collection of stars which revolve together to form the body of a greater entity called a Cosmos. This in turn floats in the Galactic Ocean. Some might call it Arcturus. The star cluster is that of the Pleiades.
However within the body of this Cosmos is a great darkness. Esoteric texts tell us it is indigo and that this is why the sky looks black at night. It is within that great darkness that the lost souls struggle to find their escape, but not knowing their way through the ‘bardo’, to give it another name, they find themselves wrestling and struggling, each more lost than the last.
Still beset by the desires of their former lives they hanker after breath and the tastes of life. As Homer records ‘they long for the taste of blood’. In this sense they are bloodthirsty, but that does not mean they are vengeful. Merely unhappy and seeking any way they can to find themselves back again in the endless chain of Life.