Secret HistorySeason 142014 · 4 episodesEpisodes1The Real Noah's ArkKnow what this is about2Hitler's Hidden Drug HabitHitler's Hidden Drug Habit Documentary discussing Hitler's fraudulent physician, his poor health and possible drug dependency.3World War I's Forgotten HeroesFormer Royal Marines commando Arthur Williams embarks on a journey to explore the experiences of nearly two million British soldiers who suffered life-changing injuries and disabilities during the First World War.4The Great Wall of China: The Hidden StoryWith access to the first nationwide survey and state-of-the-art drones mapping the Great Wall of China, this documentary offers new evidence that reveals its extraordinary magnitude, rewrites its millennia-long history and decodes its complex signals system. Using cutting-edge chemistry, the programme also finds out what has kept the wall standing for so long - a simple cooking ingredient found in kitchens across the world.Season 1Season 2Season 3Season 4Season 5Season 6Season 7Season 8Season 9Season 10Season 11Season 12Season 13Season 15Season 16Season 17Season 18
