Cities Of The Underworld

Scotland's Sin City: From plague victims being buried alive, to body snatchers, illegal distilleries and castle dungeons, Edinburgh's underground world has many stories to tell. (S1, ep 11)

Hitler's Underground Lair (Berlin): Eric Geller travels through the damp recesses of Berlin's secret bunkers. Engineered by the Nazis during WWII, their dark past is revealed. (S1, ep 6)

Rome's Hidden Empire: Host Eric Geller discovers what life was like during Emperor Nero's tyrannical reign and Augustus's reforms by peeling back the hidden history of Rome. (S1, ep 9)

Catacombs Of Death (Paris): Crypts, ancient waterfronts, waste-filled sewers, and hundreds of miles of limestone tunnels snake beneath Paris. Eric Geller examines its underworld. (S1, ep 2)

Budapest: Venture into Budapest's creepy caves with Eric Geller as he gains exclusive access to a secret WWII hospital and discovers a subterranean world below the metropolis. (S1, ep 3)

New York: What's at the heart of the Big Apple? Explore a tangle of engineering, history and secrets that make up a dark urban underworld labyrinth. (S1, ep 8)