Mysteries of the Abandoned

Pompeii's Gate to Hell (4x8)

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Near the destroyed city of Pompeii, an eerie complex of underground tunnels snake beneath a volcano, and some believe these passages were intended as a gateway to hell. Stories: 1) Berlin-Hohenschönhausen, former East Germany; 2) Drydock No. 1, California, USA; 3) Baia Archaeological Park, Naples, Italy; 4) Isla San Lucas, Costa Rica