Graham Hancock unveils stunning archaeological evidence from his new book "Underworld: A Quest for the City Below," revealing underwater ruins that challenge conventional human history. The bestselling author discusses his underwater explorations off the coasts of India, Japan, and other locations where he has discovered massive stone structures submerged beneath the ocean. Hancock presents compelling evidence suggesting these ruins represent advanced civilizations that existed before the last ice age, when sea levels were dramatically lower. The conversation explores how rising waters at the end of the ice age may have swallowed entire cities and cultures, leaving only tantalizing glimpses of humanity's lost past. Hancock describes his diving expeditions to document these underwater archaeological sites, including detailed stone carvings, architectural features, and megalithic constructions that appear far older than mainstream archaeology accepts. Art and Hancock examine the implications of these discoveries for understanding human development, questioning whether advanced civilizations rose and fell thousands of years before traditionally accepted timelines. This exploration of submerged evidence challenges listeners to reconsider the true scope and sophistication of ancient human achievement, suggesting our species may have a far more complex and advanced history than previously imagined.