Researcher and author Graham Hancock examined what he considers compelling evidence of inexplicable underwater ruins around the world. He noted that approximately 10 million square miles of Earth's most fertile land were submerged at the end of the Ice Age, just before the period traditionally associated with the rise of civilization. He described evidence of possible artificial structures discovered beneath the seas in locations around the globe. Among these is an apparent underwater city near Cuba. Hancock observed that researchers have yet to secure the funding needed to conduct a comprehensive investigation, arguing that scientific resistance stems from a prevailing mindset that such discoveries simply cannot be real. He suggested that the site could be connected to the legendary Atlantis.

Hancock also contended that the military has a far more detailed understanding of the seafloor than the public, potentially keeping some discoveries classified for strategic reasons. He criticized the scientific community's resistance to theories of lost civilizations, suggesting they reject such ideas because they challenge the established foundations of our understanding of the past.

He also recounted diving among a series of megalithic structures and a "gigantic stone circle" off the coast of Japan, which he maintains are unquestionably human-made. He further speculated that ancient civilizations may have possessed a globally shared technique for moving and manipulating enormous stones with relative ease, perhaps through an advanced science that interacted directly with the physical world through the power of the mind.