We know just the basics from public revelation about life after death, with varying accounts from private revelation giving more detail, and those details passed from one generation to another leaves each individual with their own visualization. Here is mine.
After death, I visualize the soul going upward into the spiritual world and above the Earth. Not through a tunnel but just through space. You reach an open area, well lit, kneeling. Then Christ appears to you, and your guardian Angel. You are shown quickly your entire life. Then you receive your sentence, trembling in fear. If you are damned, you are cast into hell, but I always visualized hell as being to your left, descending downward to the left, in levels at an angle, like going down a canyon. I think this is because the “right” symbolizes the direction of the good, and the left it’s opposite.
If you are saved you ascend upward to the right, like going up a mountain, either though the different levels of purgatory, or straight through the pearly gates. I think I always thought of it in this dimension to visualize it all in one point of view, that is the vantage point of where you receive the particular judgment. It’s easier for me to visualize hell, purgatory, and heaven in total together, that way, than to imagine a purely vertical dimension with hell directly below.
If you think of it objectively, you can view it purely vertically with hell below and heaven above, but if you meditate on the subjective, personal experience you will have at your judgment, this way you can visualize all three places in one visual plane, otherwise it would be alternating your visual view from above to below. This way you can imagine yourself before God’s judgment seat able to see or visually mediate on hell, purgatory, and heaven in one visual field.
I imagine hell to be dark, with caverns, and fire at its center. There is fire everywhere but at the center it is concentrated in a sea of fire. But at different levels going down the canyon are dark places of torment. I imagine the damned soul thinking into the future, in absolute horror that hell will be forever.
Purgatory in my mind has fire, but it is full of light not darkness like hell. Yet it is also foggy, nothing is clear. It is like you are in a cloud or semi-dream state. You are alone but at times allowed communication with others there and angels. In my mind’s eye, the person is in a static, passive state of purgation. On one hand they regret not suffering better in this life since suffering there is much worse, but you are in a state of peace. It’s both awful and beautiful at the same time.
Once in heaven, God willing, I imagine first seeing loved ones, then Christ, and the Virgin Mary, and then having the complete Beatific Vision of the Holy Trinity. I view heaven more like nature than a celestial city, though I think there will be both. At the top of heaven is in a sense access to the inner life of God in so far as He transcends heaven and all creation. So it would seem to me that in a sense we even rise above heaven in so far as we share in the infinite, inner life of God. At that ultimate height, even above heaven itself, it feels like it is just you and God, needing nothing else.