Go behind closed doors to explore the mysteries of the Freemasons, the secrets hidden inside Fort Knox, and the legacy of the Playboy Mansion. This marathon uncovers the stories, myths, and intrigue behind some of America's most iconic institutions. Stay up to date on all of your favorite The HISTORY Channel shows at history.com/schedule. #AmericasBookofSecrets Subscribe for more from America's Book of Secrets and other great The HISTORY Channel shows: http://histv.co/SubscribeHistoryYT Watch more America's Book of Secrets on YouTube in this playlist: https://www.youtube.com/playlist?list=PLob1mZcVWOahXrQrSF4qh4nXxElc6lo72 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.