Popularized by adventure, fantasy, and sci-fi literature, Hollow Earth theories advance the notion that Earth has a hollow interior and, possibly, a habitable inner surface. Although direct knowledge of Earth’s structure extends only 15 m (24 km) down—the deepest humans have ever drilled—the Hollow Earth hypothesis has long been refuted by the modern understanding of planet formation. However, in ancient times, subterranean realms seemed plausible and became linked with what religious concepts? Discuss
Source: The Free Dictionary