The Hollow Earth Is Filled With Giants, Germans, and A Little Sun | Atlas Obscura

Yes, you're reading that correctly, a post concerning "Hollow Earth".  Although not a religiously motivated concept per se, it is an idea that has spawned a deluded cult mind think - ie Koreshan Unity (not to be confused with David Koresh).  A sub-genre of sci-fi literature - think Jules Verne. And even a role in pseudo-history - the supposed secret journal entry of Admiral Richard Byrd.

This article actually lays out a nice basic history of the idea and it is a fun(ny) read amongst all the other battshittery.

Ah, the underworld. From time immemorial, people have believed that there is another world lying just beneath the surface of our planet. To a number of cultures—the ancient Greeks for one—it is a dark place filled with the souls of the dead. But most of these early beliefs were metaphorical or mythological in origin.

Modern science holds that that the Earth is an unbroken series of layers, crusts, and liquid magma surrounding a dense, hot core made primarily of iron and nickel. But not everyone is convinced. In the 17th century, some of the leading scientific minds of the time came up with a new theory—that the planet is actually hollow. This idea has proved incredibly durable.

Even today, there is a small cadre of Hollow Earth believers who are fighting valiantly to validate their ideas through books, websites, meetings and some extremely ambitious travel plans.

“My conception of the Hollow Earth, based on my research is that the shell of the Earth is about 800 miles thick, from the outside to the inner surface,” says Rodney Cluff, author of World Top Secret: Our Earth IS Hollow. He went even further in our phone conversation: half the planet is taken up by surface weight, and then there’s empty space, and then, something else. “Suspended in the center of that hollow is an interior sun that is divided by day and night sides,” he says, “The other part of the Hollow Earth theory is that near the North and South pole are substantial openings that lead into the interior.”

Hollow Earth theory sounds like science fiction, and is often presented as such, but some of history’s greatest scientists have subscribed to it. At one point, it seemed downright logical.

The Hollow Earth Is Filled With Giants, Germans, and A Little Sun | Atlas Obscura