The Hollow Earth Theory is a controversial hypothesis that suggests the Earth is hollow and contains an advanced civilization living inside, accessible through openings at the North and South Poles.

This theory is explored in the podcast episodes Compilation: Ancient Mysteries vol 1 and The Antarctica Conspiracies | Red Thread, which discuss the legend of Agartha, a subterranean civilization, and Admiral Richard E. Byrd's alleged encounter with an advanced civilization called the Ariani in Antarctica.

While intriguing, the Hollow Earth Theory lacks substantial scientific evidence and has been widely criticized by mainstream academia.