Journey beneath the streets of Las Vegas and London to uncover hidden tunnels, lost cities and wartime secrets. From Sin City’s buried past to Hitler’s final plans, these underground worlds reveal the history hidden below our feet. See more in this marathon from Cities of the Underworld. Watch all new episodes of Cities of the Underworld, returning soon, and stay up to date on all of your favorite The HISTORY Channel shows at history.com/schedule. #CitiesoftheUnderworld Subscribe for more from Cities of the Underworld and other great The HISTORY Channel shows: http://histv.co/SubscribeHistoryYT Check out exclusive The HISTORY Channel content: History Newsletter - https://histv.co/newsletter Website - https://histv.co/History Facebook - https://histv.co/Facebook Twitter - https://histv.co/Twitter HISTORY® is the leading destination for award-winning original series and specials that connect viewers with history in an informative, immersive, and entertaining manner across all platforms. The network’s all-original programming slate features a roster of hit series, premium documentaries, and scripted event programming.