583. The heavens are in the more elevated localities of the spiritual world, the world of spirits in those that are low-lying, and under both are the hells. The heavens are not visible to the spirits in the world of spirits except when their interior sight is opened; although they are sometimes visible as mists or as bright clouds. This is because the angels of heaven are in an interior state as to intelligence and wisdom; and for this reason they are above the sight of those who are in the world of spirits. But spirits who are in the plains and valleys see one another; and yet when they are separated there, which takes place when they are let into their interiors, then the evil spirits do not see the good spirits; but the good spirits can see the evil spirits. Nevertheless, the good spirits turn themselves away from the evil spirits; and when spirits turn themselves away they become invisible. But the hells do not appear because they are closed up. Only the entrances, which are called gates, are seen when they are opened to let in other like spirits. All the gates to the hells open from the world of spirits, and none of them from heaven.