'Edom' or 'Idumea,' as in Isaiah 34:5, signifies people who are in evil and falsities derived there.

(Референци: The Inner Meaning of the Prophets and Psalms 34)

583. The heavens there are on the higher ground, the world of spirits there is in the lower areas, and beneath both lie the hells.

The heavens are not visible to spirits in the world of spirits unless their inner sight has been opened. Sometimes they do appear, looking like gleaming white clouds. This is because heaven's angels are in a more inward state as regards their intelligence and wisdom, so they are beyond the sight of people in the world of spirits.

The spirits who are in the plains and valleys can see each other, though when they are being sorted out (which happens when they are being let into their inner natures), then evil spirits do not see the good ones. The good ones can still see the evil ones, but they turn away from them, and spirits who turn away become hard to see.

The hells themselves, though, are not visible, because they are closed. All one can see are the entrances, called gates, when they open to admit spirits like the ones already there. All the gates into the hells open from the world of spirits, none from heaven.