The final collapse of the Nazi regime in 1945 left as many questions as it did relics. This series will uncover and examine some of the most unusual and secret sites, as experts dissect and reveal the purpose of these bases, their makeup and technical design. 　　S2 E1 - Inside the Terror Factory 　　S2 E2 - Underground Superweapons 　　S2 E3 - Secrets of Vogelsang Castle 　　S2 E4-Secret Nazi...