In the 19th Century, huge stone fortresses protected leaders and their people against enemy canons. As weapons technology and warfare changed, countries began to build steel and concrete bunkers, to protect their troops in battle. The first episode examines the bunkers built in Europe before and during World War II, from the Italian Franzensfeste to Churchill’s War Room. In the second episode, we go underground in the nuclear-era shelters, including the thousands built by a paranoid Romanian leader.