S1 E2: Catacombs of Death: Paris
S1 E3: City of Caves: Budapest
S1 E4: Dracula's Underground: Bucharest
S1 E5: Freemason's Underground: Boston...
S1 E6: Hitler's Underground Lair: Berlin
S1 E7: London's Lost Cities
S1 E8: New York
S1 E9: Rome's Hidden Empire
S1 E10: Rome: The Rise
S1 E11: Scotland's Sin City
S1 E12: Secret Pagan Underground: Cappadocia
S1 E13: Underground Bootleggers: Portland
S1 E1: Beneath Vesuvius: Naples
S4 E1: Mayan Apocalypse
S4 E2: America's Ancient Ancestors
S4 E3: The Pirate Queen's Lair
S4 E4: America's Military Underground
S4 E5: Murder Tunnels
S4 E6: Templars and the Founding Fathers
S4 E7: The Lost Aztec Colony
S4 E8: Templars and the Founding Fathers