Science Channel HD The top-secret construction of a massive nuclear bunker remained concealed under a palatial West Virginia hotel for decades; experts reveal how this vast subterranean structure was one of the most closely guarded Cold War secrets in U.S. history. 2026-11-12 The longest known cave system in the world spans hundreds of miles beneath the hills of Kentucky, and containing prehistoric artifacts and ancient human remains, experts reveal a subterranean mystery that may have changed the course of U.S. history. 2026-11-12 Explorers investigate the snow-covered Ararat Mountains for remains of Noah's Ark; two separate expeditions claim discoveries in different areas, fueling debates over the truth of the story. 2026-11-12 The ten plagues of Egypt are supposedly sent by God to convince Pharaoh to free the Israelites; some scientists link these events to a volcanic eruption or climate change; could these be natural occurrences or are they divine warnings? 2026-11-12 In 1532, Spanish conquistadors encounter the advanced Inca Empire; despite their sophisticated infrastructure, the Inca falls within decades; the story of how a powerful empire is overtaken by a small group of conquistadors remains mysterious. 2026-11-12 Rameses II led Egypt through a sixty-year golden age as a powerful pharaoh; despite his recorded achievements, researchers investigate lingering mysteries regarding his wife Nefertari and his death. 2026-11-13